Filter assembly; components therefor; and, methods

ABSTRACT

Air filter assemblies and components therefor are described. The air filter assembly typically includes an air filter cartridge. Air filter cartridges including a media pack comprising at least a first stack of single facer strips are described. In examples described, at least a portion of the first stack of single facer strips is arcuate. Air filter assemblies are characterized that are configured, for example, to advantageously use such air filter cartridges. Example air filter assemblies are described that include pulse jet air cleaning systems.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuing application of U.S. Ser. No.13/685,030, filed Nov. 26, 2012, and which has issued as U.S. Pat. No.8,721,757. U.S. Ser. No. 13/685,030 is a continuation of U.S. Ser. No.12/583,965, which has issued as U.S. Pat. No. 8,317,890. U.S. Ser. Nos.13/685,030 and 12/583,965 includes the disclosure of, with edits andadditions, U.S. provisional application 61/190,495, filed Aug. 29, 2008.The complete disclosures of U.S. Ser. Nos. 13/685,030; 12/583,965 and61/190,495 are incorporated herein by reference. A claim of priority ismade to each of U.S. Ser. Nos. 13/685,030; 12/583,965 and 61/190,495 tothe extent appropriate.

FIELD OF THE DISCLOSURE

The present disclosure relates to filter arrangements for use infiltering fluids, such as air. The disclosure in part relates to airfilter arrangements including media packs that use media ascharacterized herein. The media generally comprises flutes formed into amedia pack having inlet and outlet flow faces with flutes extendingtherebetween. More specifically, the disclosure in part relates to suchmedia packs and their inclusion in serviceable filter cartridges. filterarrangements and methods of assembly and use are described. In someapplications, pulse jet cleaning assemblies are characterized.

BACKGROUND

Fluid (gas or liquid) streams can carry contaminant material therein. Inmany instances, it is desired to filter some or all of the contaminantmaterial from the air stream. For example: air flow streams to engines,for example combustion air for motorized vehicles or for powergeneration equipment; gas (for example air) streams to gas turbinesystems; gas (for example, air) streams to various combustion furnaces;and, cabin air and air in industrial systems, carry particulatecontaminant therein that should be filtered. It is preferred for suchsystems, that selected contaminant material be removed from (or have itslevel reduced in) the fluid. A variety of fluid filter arrangements havebeen developed for contaminant collection. Improvements are sought.

SUMMARY

Fluid assemblies and components therefore are described. Also methods ofassembly and use are characterized. There is no specific requirementthat a component, assembly or method include all of the features andcharacteristics characterized herein, to obtain some advantage accordingto the present disclosure.

Herein, the term “fluid” is meant to refer to the carrier fluid in whichthe material to be separated by filtration is carried. The term “fluid”is intended to include within its scope gases (for example air) and/orliquids. However, the techniques described herein are specifically, andadvantageously, developed for use with gas filter systems, specificallyair filter systems.

In an aspect to the present disclosure, a filter cartridge (for exampleair filter cartridge) is provided including a media pack comprising atleast a first media stack having a plurality of single facer stripsdefining an inlet flow face and an outlet flow face. Each single facerstrip of the plurality of single facer strips typically comprises asheet of fluted media secured to a sheet of facing media. A stack ofsingle facer strips includes a stacking bead between adjacent singlefacer strips; the stacking beads typically being adjacent a flow face,in some examples an outlet flow face, of the media pack. At least aportion of the filter media stack of single facer strips is configuredin an arcuate configuration. The term “arcuate” in this context is meantto indicate that the stack (or stack portion) is curved over an arcuateconfiguration in cross-section. A variety of arcuate configurations arepossible. In examples described, in the arcuate section, the singlefacer strips are fanned; the term “fanned” in this context indicatingthat the single facer strips (of the stack or stack portion) generallydiverge from one another an extension away from a smaller side (or end;i.e. inner or interior arc) of the arcuate shape or configuration towarda larger side (or end; i.e. outer or exterior arc) of the arcuate shapeor configuration. Typically the media pack is closed to passage ofunfiltered fluid (for example air) completely therethrough. That is, forfluid (air) entering an inlet flow face of the media pack to exit anoutlet flow face of the media pack, it typically must pass through themedia of the media pack, with filtering.

A variety of specific media pack configurations are characterized. Insome the media is configured a closed loop. In certain others, the mediaincludes at least a portion curved into an arcuate shape but does notextend through a complete closed loop.

Some arrangements comprise a single stack while others comprise morethan one. In some, one or more blocked stacks are used; in others one ormore slanted stacks are used.

Various features for filter cartridges are described, including featuresproviding for an appropriate sealing of the media pack with an aircleaner a framework or housing.

Air filter assemblies are described and depicted that are configured,for example, for use with one or more such filter cartridges. An exampleair filter assembly is described which includes a pulse jet cleaningarrangement associated therewith.

In another aspect of the present disclosure, an air filter assembly isprovided which includes at least one, and typically two or more, venturimembers associated with each filter cartridge installed therein. Thefilter cartridges can be generally in accord with those described above.

Herein, in this context the term “associated with” means that a venturimember is positioned to receive filtered air (gas) flow from the mediapack and to direct a pulse jet gas flow into the media pack. When two ormore venturi members are associated with the same filter cartridge, eachventuri member is positioned to accomplish this. In an examplecharacterized, the media pack is configured as a closed loop, with mediaextending around an open filter interior; and, each of two venturimembers is oriented to receive air (gas) flow from, and to direct aselected pulse jet into, the open filter interior.

Again, there is no specific requirement that component, assembly ormethod include all of the features characterized herein, or onlyfeatures characterized herein, to obtain some benefit according to thepresent disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary, schematic, perspective view of example filtermedia useable in selected arrangements according to the presentdisclosure.

FIG. 2 is an enlarged, schematic, cross-sectional view of a portion ofthe media depicted in FIG. 1.

FIG. 3 includes schematic views of examples of various fluted mediadefinitions.

FIG. 3A includes a schematic, fragmentary, cross-sectional view of afurther fluted media configuration in a single facer media pack.

FIG. 3B includes a schematic, fragmentary, cross-sectional view of astill further alternate flute definition in a media pack comprisingsingle facer strips.

FIG. 3C includes a schematic, fragmentary, cross-sectional view of yetanother flute definition in a media pack comprising single facer strips.

FIG. 4 is a schematic view of an example process for manufacturing mediaaccording to the present disclosure.

FIG. 5 is a schematic cross-sectional view of an optional end dart formedia flutes useable in arrangements according to the presentdisclosure.

FIG. 6 is a schematic depiction of a step of creating a stacked mediapack.

FIG. 7 is a schematic depiction of fluid flow through a stacked filtermedia pack generally analogous to the one depicted in FIG. 6, but fannedsomewhat.

FIG. 8 is a schematic, end, depiction of a media pack in accord withFIGS. 6 and 7, configured in a selected arcuate, fanned orientation.

FIG. 9 is a schematic perspective view of media pack of FIG. 8.

FIG. 10 is a second schematic perspective view of the media pack of FIG.8.

FIG. 10A is a schematic end elevational view of a first example filtercartridge incorporating the media pack of FIG. 8.

FIG. 10B is a schematic perspective view of the second example filtercartridge incorporating the media pack of FIG. 8.

FIG. 10C is a schematic end elevational view of a third example filtercartridge incorporating the media pack of FIG. 8.

FIG. 11 is a schematic perspective view of an arcuate media packincorporated into a semicircular shape with end pieces.

FIG. 12 is a schematic top perspective view of a filter cartridgeincorporating a fanned media pack configured in a complete 360°, orclosed loop, arcuate shape.

FIG. 13 is a schematic side elevational view of the cartridge of FIG.12.

FIG. 14 is a schematic top plan view of the cartridge of FIGS. 12 and13.

FIG. 15 is a schematic perspective view of a second filter cartridgeincorporating a fanned media pack, configured in a complete 360°, orclosed loop, arcuate shape, in this instance an oval shape.

FIG. 16 is a schematic top plan view of the filter cartridge of FIG. 15.

FIG. 17 is a schematic side elevational view of the cartridge of FIG.15.

FIG. 18 is a schematic perspective view of an air filter assemblyincluding at least one cartridge in accord with FIGS. 15-17 therein.

FIG. 19 is a schematic second perspective view of the air filterassembly of FIG. 18.

FIG. 20 is a schematic, exploded, access end perspective view of the airfilter assembly of FIGS. 18 and 19, depicted with a first, upper, filtercartridge installed and a second, lower, filter cartridge beinginstalled.

FIG. 21 is a second schematic, exploded, access end view analogous toFIG. 20, but depicting a retainer plate for first cartridge in explodedview as well.

FIG. 22 is an enlarged, fragmentary, schematic view of a selectedportion of FIG. 20.

FIG. 23 is a schematic access end elevational view of the assembly ofFIGS. 18 and 19.

FIG. 24 is a schematic cross-sectional view taken along 24-24, FIG. 23.

FIG. 25 is a schematic cross-sectional view taken along 25-25, FIG. 24.

FIG. 26 is a fragmentary, schematic view of selected componentry withinthe assembly of FIGS. 18, 19 and 23.

FIG. 27 is a venturi end elevational view of the componentry of FIG. 26.

FIG. 28 is a cartridge end perspective view of selected componentry ofFIG. 26, depicted with a pressure plate removed.

FIG. 29 is an enlarged, fragmentary, schematic, venturi end plan view ofselected componentry of FIG. 27.

FIG. 30 is a schematic perspective view of a further filter cartridgeincorporating a media pack according to the present disclosure.

FIG. 31 is a fragmentary, schematic, cross-sectional view depicting aportion of the media pack of the filter of FIG. 30.

FIG. 32 is a schematic, perspective, view of a slanted stack media packusable in arrangements according to the present disclosure.

FIG. 33 is a schematic top, outlet end perspective view of a filtercartridge including a media pack comprising two media pack sections eachof which is made from a slanted stack.

FIG. 34 is a second schematic top perspective view of the filtercartridge of FIG. 33.

FIG. 35 is a schematic top plan of the filter cartridge of FIGS. 33 and34.

FIG. 36 is a schematic side elevational view of the filter cartridge ofFIGS. 33 and 34.

FIG. 37 is a schematic exploded perspective view of the filter cartridgeof FIGS. 33 and 34.

FIG. 38 is a second schematic exploded perspective view of the filtercartridge of FIGS. 33 and 34.

FIG. 39 is a schematic perspective view of an end panel component of thefilter cartridge of FIGS. 33-38.

FIG. 40 is a schematic side elevational view of the end panel componentof FIG. 39.

FIG. 41 is a schematic plan view of the end panel component of FIGS. 39and 40.

FIG. 42 is a schematic perspective view of the media pack of the filtercartridge of FIGS. 33-38.

FIG. 43 is a schematic plan view of the media pack of FIG. 42.

FIG. 44 is a schematic perspective view of a first media pack section ofthe media pack of FIGS. 42 and 43.

FIG. 45 is a schematic side plan view of the media pack of FIG. 44.

FIG. 46 is a schematic perspective view of a media pack configurationincluding multiple arcuate sections.

FIG. 47 is a schematic perspective view of a further alternate mediapack configuration to those previously described herein; the media packof FIG. 47 having multiple arcuate sections including at least two,adjacent, oppositely curved arcuate sections.

FIG. 48 is a schematic perspective view of a further example media packconfiguration.

DETAILED DESCRIPTION I. Media Configurations, Generally

Fluted filter media can be used to provide fluid filter constructions ina variety of manners. One well known manner is characterized herein as az-filter construction. The term “z-filter construction” as used herein,is meant to refer to a type of filter construction in which individualones of corrugated, folded or otherwise formed filter flutes are used todefine sets of longitudinal, typically parallel, inlet and outlet filterflutes for fluid flow through the media; the fluid flowing along thelength of the flutes between opposite inlet and outlet flow ends (orflow faces) of the media. Some examples of z-filter media are providedin U.S. Pat. Nos. 5,820,646; 5,772,883; 5,902,364; 5,792,247; 5,895,574;6,210,469; 6,190,432; 6,350,296; 6,179,890; 6,235,195; Des. 399,944;Des. 428,128; Des. 396,098; Des. 398,046; and, Des. 437,401; each ofthese fifteen cited references being incorporated herein by reference.

One type of z-filter media, utilizes two specific media componentsjoined together, to form the media construction. The two components are:(1) a fluted (typically corrugated) media sheet; and, (2) a facing mediasheet. The facing media sheet is typically non-corrugated, however itcan be corrugated, for example perpendicularly to the flute direction asdescribed in U.S. provisional 60/543,804, filed Feb. 11, 2004, andpublished as PCT WO 05/077487 on Aug. 25, 2005, incorporated herein byreference.

The fluted (typically corrugated) media sheet and the facing media sheettogether, are used to define media having parallel inlet and outletflutes. In some instances, the fluted sheet and facing sheet are securedtogether and are then coiled to form a z-filter media construction. Sucharrangements are described, for example, in U.S. Pat. Nos. 6,235,195 and6,179,890, each of which is incorporated herein by reference. In certainother arrangements, some non-coiled sections or strips of fluted(typically corrugated) media secured to facing media, are stacked on oneanother, to create a filter construction. An example of this isdescribed in FIG. 11 of U.S. Pat. No. 5,820,646, incorporated herein byreference.

Herein, strips of material comprising fluted sheet secured to corrugatedsheet, which are then assembled into stacks to form media packs, aresometimes referred to as “single facer strips” or a “single facer”. Theterm “single facer strip”, and “single facer” and variants thereof, ismeant to refer to a fact that one face, i.e., a single face, of thefluted (typically corrugated) sheet, is faced by the facing sheet, ineach strip.

Typically, coiling of the fluted sheet/facing sheet (i.e., single facer)combination around itself, to create a coiled media pack, is conductedwith the facing sheet directed outwardly. Some techniques for coilingare described in U.S. provisional application 60/467,521, filed May 2,2003 and PCT Application U.S. Pat. No. 04/07927, filed Mar. 17, 2004,now published as WO 04/082795, each of which is incorporated herein byreference. The resulting coiled arrangement generally has, as the outersurface of the media pack, a portion of the facing sheet, as a result.

The term “corrugated” used herein to refer to structure in media, ismeant to refer to a flute structure resulting from passing the mediabetween two corrugation rollers, i.e., into a nip or bite between tworollers, each of which has surface features appropriate to cause acorrugation affect in the resulting media. The term “corrugation” is notmeant to refer to flutes that are formed by techniques not involvingpassage of media into a bite between corrugation rollers. However, theterm “corrugated” is meant to apply even if the media is furthermodified or deformed after corrugation, for example by the foldingtechniques described in PCT WO 04/007054, published Jan. 22, 2004,incorporated herein by reference.

Corrugated media is a specific form of fluted media. Fluted media ismedia which has individual flutes (for example formed by corrugating orfolding) extending thereacross. In general, the flutes arethree-dimensional structures formed in the filtration media thatprovide: advantageous flow along the media surface; allow foradvantageous flow of fluids through the media; and, provide forefficient contaminant removal.

Serviceable filter element or filter cartridge configurations utilizingz-filter media are sometimes referred to as “straight through flowconfigurations” or by variants thereof. In general, in this context whatis meant is that the serviceable filter elements or cartridges generallyhave an inlet flow end (or face) and an opposite exit flow end (orface), with flow entering and exiting the filter cartridge in generallythe same straight through direction. The term “serviceable” in thiscontext is meant to refer to a media containing filter cartridge that isperiodically removed and replaced from a corresponding fluid (e.g. air)cleaner or filter assembly. In some instances, each of the inlet flowend (or face) and outlet flow end (or face) will be generally flat orplanar, with the two parallel to one another. However, variations fromthis, for example non-planar faces, are possible.

A straight through flow configuration (especially for a coiled orstacked media pack) is, for example, in contrast to serviceable filtercartridges such as cylindrical pleated filter cartridges of the typeshown in U.S. Pat. No. 6,039,778, incorporated herein by reference, inwhich the flow generally makes a turn as its passes through theserviceable cartridge. That is, in a U.S. Pat. No. 6,039,778 filter, theflow enters the cylindrical filter cartridge through a cylindrical side,and then turns to exit through an end face (in forward-flow systems). Ina typical reverse-flow system, the flow enters the serviceablecylindrical cartridge through an end face and then turns to exit througha side of the cylindrical filter cartridge. An example of such areverse-flow system is shown in U.S. Pat. No. 5,613,992, incorporated byreference herein.

The term “z-filter media construction” and variants thereof as usedherein, without more, is meant to refer to any or all of: a web ofcorrugated or otherwise fluted media secured to (facing) media withappropriate sealing to allow for definition of inlet and outlet flutes;and/or a media pack constructed or formed from such media into a threedimensional network of inlet and outlet flutes; and/or, a filtercartridge or construction including such a media pack.

In FIG. 1, an example of media 1 useable in z-filter media is shown. Themedia 1 is formed from a fluted, in this instance corrugated, sheet 3and a facing sheet 4. A construction such as media 1 is deferred toherein as a single facer or single facer strip.

In general, the corrugated sheet 3, FIG. 1 is of a type generallycharacterized herein as having a regular, curved, wave pattern of flutesor corrugations 7. The term “wave pattern” in this context, is meant torefer to a flute or corrugated pattern of alternating troughs 7 b andridges 7 a. The term “regular” in this context is meant to refer to thefact that the pairs of troughs and ridges (7 b, 7 a) alternate withgenerally the same repeating corrugation (or flute) shape and size.(Also, typically in a regular configuration each trough 7 b issubstantially an inverse of each ridge 7 a.) The term “regular” is thusmeant to indicate that the corrugation (or flute) pattern comprisestroughs and ridges with each pair (comprising an adjacent trough andridge) repeating, without substantial modification in size and shape ofthe corrugations along at least 70% of the length of the flutes. Theterm “substantial” in this context, refers to a modification resultingfrom a change in the process or form used to create the corrugated orfluted sheet, as opposed to minor variations from the fact that themedia sheet 3 is flexible. With respect to the characterization of arepeating pattern, it is not meant that in any given filterconstruction, an equal number of ridges and troughs is necessarilypresent. The media 1 could be terminated, for example, between a paircomprising a ridge and a trough, or partially along a pair comprising aridge and a trough. (For example, in FIG. 1 the media 1 depicted infragmentary has eight complete ridges 7 a and seven complete troughs 7b.) Also, the opposite flute ends (ends of the troughs and ridges) mayvary from one another. Such variations in ends are disregarded in thesedefinitions, unless specifically stated. That is, variations in the endsof flutes are intended to be covered by the above definitions.

In the context of the characterization of a “curved” wave pattern ofcorrugations, the term “curved” is meant to refer to a corrugationpattern that is not the result of a folded or creased shape provided tothe media, but rather the apex 7 a of each ridge and the bottom 7 b ofeach trough is formed along a radiused curve. A typical radius for suchz-filter media would be at least 0.25 mm and typically would be not morethan 3 mm.

An additional characteristic of the particular regular, curved, wavepattern depicted in FIG. 1, for the corrugated sheet 3, is that atapproximately a midpoint 30 between each trough and each adjacent ridge,along most of the length of the flutes 7, is located a transition regionwhere the curvature inverts. For example, viewing back side or face 3 a,FIG. 1, trough 7 b is a concave region, and ridge 7 a is a convexregion. Of course when viewed toward front side or face 3 b, trough 7 bof side 3 a forms a ridge; and, ridge 7 a of face 3 a, forms a trough.(In some instances, region 30 can be a straight segment, instead of apoint, with curvature inverting at ends of the segment 30.)

A characteristic of the particular regular, wave pattern fluted (in thisinstance corrugated) sheet 3 shown in FIG. 1, is that the individualcorrugations are generally straight. By “straight” in this context, itis meant that through at least 70%, typically at least 80% of the lengthbetween edges 8 and 9, the ridges 7 a and troughs 7 b do not changesubstantially in cross-section. The term “straight” in reference tocorrugation pattern shown in FIG. 1, in part distinguishes the patternfrom the tapered flutes of corrugated media described in FIG. 1 of WO97/40918 and PCT Publication WO 03/47722, published Jun. 12, 2003,incorporated herein by reference. The tapered flutes of FIG. 1 of WO97/40918, for example, would be a curved wave pattern, but not a“regular” pattern, or a pattern of straight flutes, as the terms areused herein.

Referring to the present FIG. 1 and as referenced above, the media 1 hasfirst and second opposite edges 8 and 9. When the media 1 is formed intoa media pack, in general edge 9 will form an inlet end for the mediapack and edge 8 an outlet end, although an opposite orientation ispossible.

Adjacent edge 8 is provided a sealant bead 10, sealing the corrugatedsheet 3 and the facing sheet 4 together. Bead 10 will sometimes bereferred to as a “single facer” bead, since it is a bead between thecorrugated sheet 3 and facing sheet 4, which forms the single facer ormedia strip 1. Sealant bead 10 seals closed individual flutes 11adjacent edge 8, to passage of air therefrom.

Adjacent edge 9, is provided seal bead 14. Seal bead 14 generally closesflutes 15 to passage of unfiltered fluid therein, adjacent edge 9. Bead14 would typically be applied as strips of the media 1 are secured toone another during stacking Thus bead 14 will form a seal between a backside 17 of facing sheet 4, and side 18 of the next adjacent corrugatedsheet 3. When the media 1 is cut in strips and stacked, instead ofcoiled, bead 14 is referenced as a “stacking bead.” (When bead 14 isused in a coiled arrangement formed from media 1, not depicted herein,it is referenced as a “winding bead.”)

Referring to FIG. 1, once the media 1 is incorporated into a media pack,for example by stacking, it can be operated as follows. First, air inthe direction of arrows 12, would enter open flutes 11 adjacent end 9.Due to the closure at end 8, by bead 10, the air would pass through themedia, for example as shown by arrows 13. It could then exit the mediapack, by passage through open ends 15 a of the flutes 15, adjacent end 8of the media pack. Of course operation could be conducted with air flowin the opposite direction.

For the particular arrangement shown herein in FIG. 1, the parallelcorrugations 7 a, 7 b are generally straight completely across themedia, from edge 8 to edge 9. Straight flutes or corrugations can bedeformed or folded at selected locations, especially at ends.Modifications at flute ends for closure are generally disregarded in theabove definitions of “regular,” “curved” and “wave pattern.”

Z-filter constructions which do not utilize straight, regular curvedwave pattern corrugation shapes are known. For example in Yamada et al.U.S. Pat. No. 5,562,825 corrugation patterns which utilize somewhatsemicircular (in cross section) inlet flutes adjacent narrow V-shaped(with curved sides) exit flutes are shown (see FIGS. 1 and 3, of U.S.Pat. No. 5,562,825). In Matsumoto, et al. U.S. Pat. No. 5,049,326circular (in cross-section) or tubular flutes defined by one sheethaving half tubes attached to another sheet having half tubes, with flatregions between the resulting parallel, straight, flutes are shown, seeFIG. 2 of Matsumoto '326. In Ishii, et al. U.S. Pat. No. 4,925,561(FIG. 1) flutes folded to have a rectangular cross section are shown, inwhich the flutes taper along their lengths. In WO 97/40918 (FIG. 1),flutes or parallel corrugations which have a curved, wave patterns (fromadjacent curved convex and concave troughs) but which taper along theirlengths (and thus are not straight) are shown. Also, in WO 97/40918flutes which have curved wave patterns, but with different sized ridgesand troughs, are shown.

In general, the filter media is a relatively flexible material,typically a non-woven fibrous material (of cellulose fibers, syntheticfibers or both) often including a resin therein, sometimes treated withadditional materials. Thus, it can be conformed or configured into thevarious corrugated patterns, without unacceptable media damage. Also, itcan be readily coiled or otherwise configured for use, again withoutunacceptable media damage. Of course, it must be of a nature such thatit will maintain the required corrugated configuration, during use.

In the corrugation process, an inelastic deformation is caused to themedia. This prevents the media from returning to its original shape.However, once the tension is released the flute or corrugations willtend to spring back, recovering only a portion of the stretch andbending that has occurred. The facing media sheet is sometimes tacked tothe fluted media sheet, to inhibit this spring back in the corrugatedsheet. Such tacking is shown at 20.

Also, typically, the media contains a resin. During the corrugationprocess, the media can be heated to above the glass transition point ofthe resin. When the resin then cools, it will help to maintain thefluted shapes.

The media of the corrugated sheet 3 facing sheet 4 or both, can beprovided with a fine fiber material on one or both sides thereof, forexample in accord with U.S. Pat. No. 6,673,136, incorporated herein byreference. In some instances, when such fine fiber material is used, itmay be desirable to provide the fine fiber on the upstream side of thematerial and inside the flutes. When this occurs, air flow, duringfiltering, will typically be into the edge comprising stacking bead.

An issue with respect to z-filter constructions relates to closing ofthe individual flute ends. Although alternatives are possible, typicallya sealant or adhesive is provided, to accomplish the closure. As isapparent from the discussion above, in typical z-filter media,especially that which uses straight flutes as opposed to tapered flutesand sealant for flute seals, large sealant surface areas (and volume) atboth the upstream end and the downstream end are needed. High qualityseals at these locations are critical to proper operation of the mediastructure that results. The high sealant volume and area, creates issueswith respect to this.

Attention is now directed to FIG. 2, in which a z-filter mediaconstruction 40 utilizing a regular, curved, wave pattern corrugatedsheet 43, and a non-corrugated flat sheet 44, i.e., a single facer stripis schematically depicted. The distance D1, between points 50 and 51,defines the extension of flat media 44 in region 52 underneath a givencorrugated flute 53. The length D2 of the arcuate media for thecorrugated flute 53, over the same distance D1 is of course larger thanD1, due to the shape of the corrugated flute 53. For a typical regularshaped media used in fluted filter applications, the linear length D2 ofthe media 53 between points 50 and 51 will often be at least 1.2 timesD1. Typically, D2 would be within a range of 1.2-2.0 times D1,inclusive. One particularly convenient arrangement for air filters has aconfiguration in which D2 is about 1.25-1.35×D1. Such media has, forexample, been used commercially in Donaldson Powercore™ Z-filterarrangements. Another potentially convenient size would be one in whichD2 is about 1.4-1.6 times D1. Herein the ratio D2/D1 will sometimes becharacterized as the flute/flat ratio or media draw for the corrugatedmedia.

In the corrugated cardboard industry, various standard flutes have beendefined. For example the standard E flute, standard X flute, standard Bflute, standard C flute and standard A flute. FIG. 3, attached, incombination with Table A below provides definitions of these flutes.

Donaldson Company, Inc., (DCI) the assignee of the present disclosure,has used variations of the standard A and standard B flutes, in avariety of z-filter arrangements. These flutes are also defined in TableA and FIG. 3.

TABLE A (Flute definitions for FIG. 3) DCI A Flute/flat = 1.52:1; TheRadii (R) are as follows: Flute: R1000 = .0678 inch (1.72 mm); R1001 =.058 inch (1.48 mm); R1002 = .058 inch (1.46 mm); R1003 = .068 inch(1.73 mm); DCI B Flute/flat = 1.32:1; The Radii (R) are as follows:Flute: R1004 = .060 inch (1.52 mm); R1005 = .052 inch (1.32 mm); R1006 =.050 inch (1.27 mm); R1007 = .062 inch (1.58 mm); Std. E Flute/flat =1.24:1; The Radii (R) are as follows: Flute: R1008 = .020 inch (.51 mm);R1009 = .030 inch (.76 mm); R1010 = .010 inch (.25 mm); R1011 = .040inch (1.02 mm); Std. X Flute/flat = 1.29:1; The Radii (R) are asfollows: Flute: R1012 = .025 inch (.64 mm); R1013 = .015 inch (.38 mm);Std. B Flute/flat = 1.29:1; The Radii (R) are as follows: Flute: R1014 =.041 inch (1.04 mm); R1015 = .031 inch (.787 mm); R1016 = .031 inch(.787 mm); Std. C Flute/flat = 1.46:1; The Radii (R) are as follows:Flute: R1017 = .072 inch (1.83 mm); R1018 = .062 inch (1.58 mm); Std. AFlute/flat = 1.53:1; The Radii (R) are as follows: Flute: R1019 = .072inch (1.83 mm); R1020 = .062 inch (1.58 mm).

Of course other, standard, flutes definitions from the corrugated boxindustry are known.

In general, standard flute configurations from the corrugated boxindustry can be used to define corrugation shapes or approximatecorrugation shapes for corrugated media. Comparisons above between theDCI A flute and DCI B flute, and the corrugation industry standard A andstandard B flutes, indicate some convenient variations.

It is noted that alternative flute definitions such as thosecharacterized in U.S. Ser. No. 12/215,718, filed Jun. 26, 2008; and Ser.No. 12/012,785, filed Feb. 4, 2008 can be used, with air cleanerfeatures as characterized herein below. The complete disclosures of eachof U.S. Ser. Nos. 12/215,718 and 12/012,785 are incorporated herein byreference.

In FIGS. 3A-3C, cross-sectional views of exemplary portions offiltration media are shown wherein the fluted sheet has one or morenon-peak ridge extending along at least a portion of the flute length.FIG. 3A shows a fluted sheet having one non-peak ridge provided betweenadjacent peaks, and FIGS. 3B and 3C show fluted sheets having twonon-peak ridges between adjacent peaks. The non-peak ridges can extendalong the flute length any amount including, for example, an amount of20% of the flute length to 100% of the flute length. In addition, thefluted sheet can be provided without non-peak ridges between alladjacent peaks, and can be provided with differing numbers of non-peakridges between adjacent peaks (e.g., alternating zero, one, or twonon-peak ridges in any arrangement). The presence of non-peak ridges canhelp provide more media available for filtration in a given volume, andcan help reduce stress on the fluted sheet thereby allowing for asmaller radius at the peaks and therefore reduced media masking. Suchmedia can be used in arrangements according to the present disclosure.

II. Manufacture of Stacked Media Configurations Using Fluted Media,Generally

In FIG. 4, one example of a manufacturing process for making a mediastrip corresponding to strip 1, FIG. 1 is shown. In general, facingsheet 64 and the fluted (corrugated) sheet 66 having flutes are broughttogether to form a media web 69, with an adhesive bead locatedtherebetween at 70. The adhesive bead 70 will form a single facer bead14, FIG. 1.

The term “single facer bead” references a sealant bead positionedbetween layers of a single facer; i.e., between the fluted sheet andfacing sheet.

An optional darting process occurs at station 71 to form center dartedsection 72 located mid-web. The z-filter media or Z-media strip 74 canbe cut or slit at 75 along the bead 70 to create two pieces 76, 77 ofz-filter media 74, each of which has an edge with a strip of sealant(single facer bead) extending between the corrugating and facing sheet.Of course, if the optional darting process is used, the edge with astrip of sealant (single facer bead) would also have a set of flutesdarted at this location. The strips or pieces 76, 77 can then be cutacross, into single facer strips for stacking, as described below inconnection with FIG. 6.

Techniques for conducting a process as characterized with respect toFIG. 4 are described in PCT WO 04/007054, published Jan. 22, 2004incorporated herein by reference.

Still in reference to FIG. 4, before the z-filter media 74 is putthrough the darting station 71 the media 74 must be formed. In theschematic shown in FIG. 4, this is done by passing a flat sheet of media92 through a pair of corrugation rollers 94, 95. In the schematic shownin FIG. 4, the flat sheet of media 92 is unrolled from a roll 96, woundaround tension rollers 98, and then passed through a nip or bite 102between the corrugation rollers 94, 95. The corrugation rollers 94, 95have teeth 104 that will give the general desired shape of thecorrugations after the flat sheet 92 passes through the nip 102. Afterpassing through the nip 102, the flat sheet 92 becomes corrugated and isreferenced at 66 as the corrugated sheet. The corrugated (i.e., fluted)media sheet 66 is then secured to facing media sheet 64. (Thecorrugation process may involve heating the media, in some instances.)

Still in reference to FIG. 4, the process also shows the facing sheet 64being routed to the darting process station 71. The facing sheet 64 isdepicted as being stored on a roll 106 and then directed to thecorrugated sheet 66 to form the Z-media 74. The corrugated sheet 66 andthe facing sheet 64 are secured together by adhesive or by other means(for example by sonic welding).

Referring to FIG. 4, an adhesive line 70 is shown used to securecorrugated sheet 66 and facing sheet 64 together, as the sealant bead.Alternatively, the sealant bead for forming the facing bead could beapplied as shown as 70 a. If the sealant is applied at 70 a, it may bedesirable to put a gap in the corrugation roller 95, and possibly inboth corrugation rollers 94, 95, to accommodate the bead 70 a.

The type of corrugation provided to the corrugated media is a matter ofchoice, and will be dictated by the corrugation or corrugation teeth ofthe corrugation rollers 94, 95. One typical type of flute pattern willbe a regular, typically curved, wave pattern corrugation, of straightflutes, as defined herein above. A typical regular curved wave patternused, would be one in which the distance D2, as defined above, in acorrugated pattern is at least 1.2 times the distance D1 as definedabove. In one typical application, typically D2=1.25-1.35×D1; in anotherD2=1.4−1.6×D1. In some instances the techniques may be applied withcurved wave patterns that are not “regular,” including, for example,ones that do not use straight flutes.

As described, the process shown in FIG. 4 can be used to create thecenter darted section 72. FIG. 5 shows, in cross-section, one of theflutes after darting and slitting.

A fold arrangement 118 can be seen to form a darted flute 120 with fourcreases 121 a, 121 b, 121 c, 121 d. The fold arrangement 118 includes aflat first layer or portion 122 that is secured to the facing sheet 64.A second layer or portion 124 is shown pressed against the first layeror portion 122. The second layer or portion 124 is preferably formedfrom folding opposite outer ends 126, 127 of the first layer or portion122.

Still referring to FIG. 5, two of the folds or creases 121 a, 121 b willgenerally be referred to herein as “upper, inwardly directed” folds orcreases. The term “upper” in this context is meant to indicate that thecreases lie on an upper portion of the entire fold 120, when the fold120 is viewed in the orientation of FIG. 5. The term “inwardly directed”is meant to refer to the fact that the fold line or crease line of eachcrease 121 a, 121 b, is directed toward the other.

In FIG. 5, creases 121 c, 121 d, will generally be referred to herein as“lower, outwardly directed” creases. The term “lower” in this contextrefers to the fact that the creases 121 c, 121 d are not located on thetop as are creases 121 a, 121 b, in the orientation of FIG. 5. The term“outwardly directed” is meant to indicate that the fold lines of thecreases 121 c, 121 d are directed away from one another.

The terms “upper” and “lower” as used in this context are meantspecifically to refer to the fold 120, when viewed from the orientationof FIG. 5. That is, they are not meant to be otherwise indicative ofdirection when the fold 120 is oriented in an actual product for use.

Based upon these characterizations and review of FIG. 5, it can be seenthat a preferred regular fold arrangement 118 according to FIG. 5 inthis disclosure is one which includes at least two “upper, inwardlydirected, creases.” These inwardly directed creases are unique and helpprovide an overall arrangement in which the folding does not cause asignificant encroachment on adjacent flutes.

A third layer or portion 128 can also be seen pressed against the secondlayer or portion 124. The third layer or portion 128 is formed byfolding from opposite inner ends 130, 131 of the third layer 128.

Another way of viewing the fold arrangement 118 is in reference to thegeometry of alternating ridges and troughs of the corrugated sheet 66.The first layer or portion 122 is formed from an inverted ridge. Thesecond layer or portion 124 corresponds to a double peak (afterinverting the ridge) that is folded toward, and in preferredarrangements, folded against the inverted ridge.

Techniques for providing the optional dart described in connection withFIG. 5, in a preferred manner, are described in PCT WO 04/007054,incorporated herein by reference. Other techniques for media managementare described in PCT application U.S. Pat. No. 04/07927, filed Mar. 17,2004, incorporated herein by reference.

Techniques described herein are well adapted for use of media packs thatresult from arrangements that, instead of being formed by coiling, areformed from a plurality of strips of single facer.

Opposite flow ends or flow faces of the media pack can be provided witha variety of different definitions. In many arrangements, the ends aregenerally flat and perpendicular to one another.

The flute seals (single facer bead, winding bead or stacking bead) canbe formed from a variety of materials. In various ones of the cited andincorporated references, hot melt or polyurethane seals are described aspossible for various applications. These are useable for applicationsdescribed herein.

In FIG. 6, schematically there is shown a step of forming a stackedz-filter media pack from strips of z-filter media, each strip being afluted sheet secured to a facing sheet. Referring to FIG. 6, singlefacer strip 200 is being shown added to a stack 201 of strips 202analogous to strip 200. Strip 200 can be cut from either of strips 76,77, FIG. 4. At 205, FIG. 6, application of a stacking bead 206 is shown,between each layer corresponding to a strip 200, 202 at an opposite edgefrom the single facer bead or seal. (Stacking can also be done with eachlayer being added to the bottom of the stack, as opposed to the top.)

Referring to FIG. 6, each strip 200, 202 has front and rear edges 207,208 and opposite side edges 209 a, 209 b. Inlet and outlet flutes of thecorrugated sheet/facing sheet combination comprising each strip 200, 202generally extend between the front and rear edges 207, 208, and parallelto side edges 209 a, 209 b.

Still referring to FIG. 6, in the media pack 201 being formed, oppositeflow faces are indicated at 210, 211. The selection of which one offaces 210, 211 is the inlet end face and which is the outlet end face,during filtering, is a matter of choice. In some instances the stackingbead 206 is positioned adjacent the upstream or inlet face 211; inothers the opposite is true. The flow faces 210, 211, extend betweenopposite side faces 220, 221.

The stacked media pack 201 shown being formed in FIG. 6, is sometimesreferred to herein as a “blocked” stacked media pack. The term “blocked”in this context, is an indication that the arrangement is formed to arectangular block in which all faces are 90° relative to all adjoiningwall faces. Alternate configurations are possible, as discussed below inconnection with certain of the remaining figures.

It is noted that a blocked, stacked arrangement corresponding to FIG. 6is described in the prior art of U.S. Pat. No. 5,820,646, incorporatedherein by reference. It is also noted that stacked arrangements aredescribed in U.S. Pat. Nos. 5,772,883; 5,792,247; U.S. Provisional60/457,255 filed Mar. 25, 2003; and U.S. Ser. No. 10/731,564 filed Dec.8, 2003. All four of these latter references are incorporated herein byreference. It is noted that a stacked arrangement shown in U.S. Ser. No.10/731,504, is a slanted stacked arrangement.

III. Media Packs with Arcuate Sections, Generally

It is noted that a media pack generally in accord with the descriptionabove for FIG. 6, can be configured so that at least a portion thereofcomprises a generally “arcuate” configuration, portion or shape. Thiswill be understood by reference to FIGS. 7-10.

Referring first to FIG. 7, a general flow pattern for a stack of stripsof media, each strip generally corresponding to a fluted sheet securedto a facing sheet in accord with the descriptions herein above for FIGS.1-2, for example, is depicted. Referring to FIG. 7, at 300 a schematicfragmentary perspective view of such a stack is provided. The portion ofthe stack 300 depicted in FIG. 7, comprises four single facer strips301, stacked with one another. Each single facer strip 301, comprises afluted sheet 303 secured to a facing sheet 304. Referring to FIG. 7, at307, a single facer seal (sealing) bead in each of sheets 301 isdepicted. The single facer sealing bead 307 provides a seal between thefluted sheet 303 and the facing sheet 304, within each single facerstrip 301.

The seal bead 307 is typically located adjacent an edge of each singlefacer strip 301, that edge being identified on FIG. 7 at 301 e. Forexample, when manufactured in accord with the process of FIG. 4, thesealant bead 307 is flush with the edge of the single facer strip 301 inwhich it is positioned, since the seal bead 307 is cut along with themedia sheets (303, 304) to form the adjacent the edge 301 e of thesingle facer strip 301. On the other hand, in alternate manufacturingapproaches, the sealant bead corresponding to the single facer bead 307could be positioned spaced between a fluted sheet and a facing sheetthat are not cut, and thus could be positioned recessed slightly fromthe edge to which it is adjacent. Typically, the single facer bead 307when characterized herein as “adjacent” an associated edge 301 e, iseither positioned flush with that edge, or is positioned spaced fromthat edge no greater than 25 mm, and typically no greater than 12 mm,and often within a distance of 5 mm or less. When it is said that thebead is “positioned” within a distance as indicated, it is meant that atleast an edge of the bead is within the identified distance from theassociated media edge.

Along an opposite media edge 301 f, each of the strips 301 is secured toa next adjacent one of the strips 301, by a stacking bead, or a seal,indicated generally at 308. Stacking bead or seal 308, then, provides aseal for selected flutes, adjacent edge 301 f. It is noted that whenmanufactured in accord with the processes characterized in FIG. 4 forexample, stacking bead 308 is typically positioned recessed slightlyfrom edge 301 f with which it is adjacent. This is to inhibit, duringformation and cure, overflow of sealant material beyond the edge 301 f,potentially inhibiting flow from outlet flutes. Again, when it is saidthat the stacking bead 308 is positioned adjacent media edge 301 f, itis meant that it is either positioned flush with the media edge, or ispositioned spaced therefrom by a distance of no greater than 25 mm,typically no greater than 12 mm, usually by a distance no greater than 5mm. By this it is not meant that the entire bead is so located, but atleast an edge of the bead is so located.

In FIG. 7, airflow is depicted by arrows 310. It is noted that arrow 310x, depicts the flow of air to the media pack 301 along a flow facegenerally defined at edges 301 e of each media strip 301. This couldcomprise, for example, air to be filtered. This air is inhibited fromentering exit flutes, by single facer seals or beads 307, and thusenters spaces 314 between strips 301. Air is inhibited from leaving end301 f, by stacking bead 308, and thus must pass through the media intooutlet flutes, to leave in the general direction shown by exit arrow 310y. It is noted that a media stack 300 can be operated with an oppositeair flow, i.e., into edges 301 f and exiting edges 301 e, in someapplications.

In general, it is noted that in FIG. 7, stack 300 has been modified fromstack 210, FIG. 6, in that adjacent edges 301 e of individual singlefacer strips 301 have been spread apart slightly. Herein, this will begenerally characterized as configuring the stack 300 in a “fanned”configuration. This will be understood more generally, by reference toFIGS. 8-10.

Before turning to FIGS. 8-10, and still referring to FIG. 7, it is notedthat for the assembly of FIG. 7, the stack 300 is depicted with thefacing sheets 304 above the associated fluted sheet 303 of each singlefacer strip 301. This is an opposite configuration of that shown in FIG.6, in which the fluted sheet of each strip is positioned above thefacing sheet. It is noted that either orientation can be used, and theprinciples of operation would not change. Further, in connection withFIG. 7, it is noted that the fluted sheets 303 are shown as if formedfrom a folding operation, as opposed to having a rounded shape, (forexample that of FIGS. 1 and 2), resulting from being corrugated inaccord with descriptions associated with those figures. Corrugatedshapes can be used, as well as alternate flute shapes.

Referring to FIG. 7, it is noted that the individual strips 301 withinthe stack 300 are not parallel to one another, but rather diverge fromone another in extension from one flow face, adjacent end 301 f, towarda second flow face, adjacent end 301 e. Typically the amount ofseparation from this divergence, which is characteristic of a fannedarrangement as described herein, will increase in extension from theoutlet flow face to the inlet flow face, for normal filtering operation.By the term “normal filtering operation” as used herein, and variantsthroughout, reference is meant to a general direction of air flow duringa filtering operation by the media pack.

Attention is now directed to FIG. 8. In FIG. 8, stack 300 is viewablefrom a side or side edge. Thus individual single facer strips 301 can beviewed. Referring to FIG. 8, instead of being maintained in a blockedstacked configuration in accord with FIG. 6, again stack 300 has beenfanned around stacking bead 308. It can be seen that this provides anarcuate configuration 320. In this context the term “arcuate” is meantto refer to the fact that when viewed from a cross-section or side, thestrip of strips defines an arcuate pattern including an inner orinterior arc, i.e., an arc adjacent the narrow side 300 i, and an outeror exterior arc, i.e., an arc adjacent the wider, outer, end 300 x.

Still referring to FIG. 8, it is noted that although alternatives arepossible the typical direction of air flow during a filtering operationis depicted at arrows 310 x, 310 y. As described in connection with FIG.7, arrow 310 x generally is shown as the direction of air flow during anormal filtering operation, entering fanned media pack 300. Arrow 310 ygenerally shows a direction of filtered air exit from fanned media pack300.

Still referring to FIG. 8, media pack 300, in the example shown having afanned configuration 320, can, again, be characterized as having anarcuate shape with a inner, smaller, arcuate face 300 i, and an oppositeouter, larger arcuate face 300 x. Alternately stated, the maximallyfanned or spread ends of the various strips 301, are generally alongface 300 x, and the minimally fanned or minimally spread ends aregenerally along face 300 i. Although alternatives are possible, atypical fanned arrangement, for reasons stated below, the spread orfanned end or face 300 x will generally be the upstream end or inletface for normal filtering flow; and, minimally spread or minimallyfanned end 300 i will typically be the outlet end or face, for typicalfiltering flow operation. Advantages which result from this, arediscussed further below.

Herein, in some instances, a reference will be made to a “internal” or“inner” arc of a fanned media pack. Referring to FIG. 8, the internalarc is meant to reference an arc between opposite end strips, forexample between strips 301 a, 301 b, when measured through the mediapack 300. Alternately stated, the “internal arc” is the arc over whichthe media pack is fanned, measured between end strips of the pack. Ifthe media pack is coiled in a loop, the internal arc is 360°.

It is noted that in some applications the techniques described herein, aportion of the media pack can be fanned, while an alternate portion(s)or an additional portion(s) is not. When reference is meant to aninternal arc in those instances, reference is meant to an arc throughthe media pack between end sheets (of single facer), in the arcuateportion.

FIG. 9, a perspective view of stack 300 in its fanned configuration 320is depicted. Individual single facer strips 301 can be seen ascomprising fluted sheet 303 secured to a facing sheet 304, and sealedthereto, adjacent edge 301 e, by single facer sealer beads 307.

In FIG. 10, a second perspective view of media pack 300 in fannedconfiguration 320 is shown.

A number of advantages can be obtained, by configuring a media packcomprising a stack of single facer strips into a fanned or arcuateconfiguration, in which individual single facer strips are spread apartadjacent the upstream ends or face 300 x.

A first of these advantages, relates to the issue of masking. Ingeneral, wherever a fluted sheet contacts a facing sheet (more generallywhere two adjacent media sheets connect), masking of media occurs.Masked media sections are inhibited from efficient involvement in thefiltering operation. It has been found that as long as two adjacentsheets (for example of fluted sheet and facing sheet) are spaced apartby no more than 0.0035 inch (0.09 mm), masking can be an issue.

Fanning the sheets apart prevents a sheet of one single facer strip fromcontacting a sheet of the next adjacent strip (or at least being withina masking proximity, i.e. 0.0035 inch or 0.08 mm, of the next adjacentstrip), at least along the upstream face 300 x where the fanning spreadsthe strips apart the most.

In general, any fanning will lead to improved properties in the mediapack for filtering, since it reduces masking Generally, it is desirableto fan the individual layers apart sufficiently so that along at least25%, typically at least 50%; and, preferably 70% or more, of the lengthsof the flutes, from the upstream single facer strip ends 300 x towardthe downstream single facer strip ends 300 y, the individual flutes ofone single facer strip 301 are spaced from the next adjacent singlefacer strip by at least 0.0035 inch (0.09 mm) or more. The amount ofspreading at the end 300 x which will provide for this, will bedependent, in part, upon the flute length, i.e. a length of the strips301 between the upstream ends 300 x and the downstream ends 300 i. Ingeneral, however, for any given selected media pack 300, the desirableamount of spread is a simple trigonometric calculation based upon theflute length of the strips 301. In some instances, a diverging anglebetween adjacent strips of at least 0.5°, and sometimes 1° or more, willbe sufficient. In any event, fanning can provide advantage with manyalternate depths (flute length) of media packs, including, for example,ones with flute length of at least 4 inches (10.2 cm) for example 5-12inches (12.7-30.5 cm).

The advantage discussed in the previous several paragraphs relates to aninhibition of masking, which is accomplished by providing a relativelysmall amount spacing between at least portions individual strips 301. Asthe strips 301 are spread apart (by the fanning) even further,additional advantages are obtained. For example as the entrance volumeat the inlet face 300 x is opened up, inlet air (fluid) is not forcedinto the narrow flute shapes, but rather can enter the larger volumebetween the individual strips. This provides a number of effectsrelating generally to improvement in inlet end restriction (air) flow.For example the air (fluid) entering the volume is not forced toaccelerate into narrow flute shape volumes, as it is for a blocked,stacked, arrangement in accord with FIG. 6. This means that the air(fluid) can more readily turn to pass through the media with lessrestriction being involved. The dust then settles and collects morereadily, with lower restriction provided by the media pack.

In addition, as the flute sheets are spread apart, a larger volume forloading dust is provided. This can lead to a longer filter life.

In applications in which the contaminant is light and fluffy, forexample in an air filter for combine operation (for harvesting beans orother crops) the contaminant includes a substantial amount of “fuzz”from the matter being handled. A fanned arrangement can be advantageousin such applications since the inlet volume is relatively large, forhandling such materials.

In general terms, a conventional pleated element is constrained byhaving the outlet pleat channels roughly equal to the inlet pleatchannels. The fanned stacks of single facer strips of mediacharacterized herein, allow the inlet volume to be substantially largerthan the outlet channel volume. Thus the fan configuration provides moreopen channel area for low density contaminate loading and better usesthe space available for the air cleaner assembly. Conversely, the onlyway to achieve an equivalent amount of loading volume with a pleatedelement would require a near equal amount of clean air volume for theoutlet channel, which volume is under utilized, from a volumeutilization stand point.

Another advantage to the fanning of single facer strips into an arcuatepattern, is that unusual shaped housing volumes can be more efficientlyused. That is, the arcuate shapes allow for media pack configurationsthat can be adapted for efficient use of restricted housing volumes orshapes. For example, the air filter assembly may be incorporated in alocation of limited or restricted shape. The ability to fan the mediapack into a uniquely shaped cartridge, can allow for selection ofcartridge shape to accommodate non-regularly shaped or sized spaces.

Also, fanning the media pack also allows for advantageous media packadaptation in reverse pulse systems (pulse jet cleaning systems). Use ofsuch media packs in association with reverse pulse cleaning is describedbelow, in association with FIGS. 18-29.

It will be understood, then, that depending on a number of individualstrips 301 contained within the pack 300, a media pack (or portion of amedia pack) generally as characterized herein; i.e., comprising a stackof single facer strips 301, (with individual strips being secured to oneanother along adjacent an edge by a stacking bead 308), can beconfigured by a variety of fanned, arcuate, shapes. There is no specificrequirement that the arcuate (for example fanned, arcuate) shape extendover any selected, specific arc, or that it be fanned only to a circulararc. A variety of alternate shapes, including up to 360° internal arc(closed loop), are possible. Further, fanning can be along an oval arc,(for example an elliptical arc, a circular arc, or alternate arc shapes.

It is noted that to facilitate formation of media stack 300, into anarced stack 320, it may be desirable that the stacking bead indicatedgenerally at 308, FIG. 10 comprise a sealing material sufficientlyflexible to facilitate the arcuate fanning. It is anticipated that afoamed polyurethane sealant, of the type characterized herein below asalso useful molded-in-place side sections and housing seals, can be usedfor such an application. However in some instances, a hot melt whichalso can typically be used for the single facer bead 307, could be usedfor a stacking bead 308.

From the above, then, it is apparent that advantages can be obtainedfrom incorporating arcuate (in some instances fanned) media packs (orportions of media packs) of single facers strips, into filtercartridges. However, it is generally required to configure the mediapacks with other cartridge features, to ensure that the cartridge can beinstalled in an air filter assembly without air being able to bypassfiltering flow through the media. Three examples of incorporating mediapack 300 into such a filter cartridge are depicted herein in FIGS.10A-10C.

Referring to FIG. 10A, fanned media, arcuate, pack 320 is configured ina cartridge 325. Cartridge 325 is constructed analogously to thosedescribed in U.S. provisional application 61/135,595, filed Jul. 22,2008 and incorporated herein by reference. In particular, a preform 326is formed having sides 327, 328 and a seal arrangement 329 thereon. (Insome instances seal material of the seal arrangement can be applied topreform 326 after a remainder of the cartridge 325 is formed). The mediapack 320 is positioned between the sides 328, generally adhered theretoby sealant bead adjacent end 300 x, for example at 330, 331. Oppositeends 332, 333, FIG. 10, of media pack 300 are sealed closed by moldedside pieces (only one of which is viewable in FIG. 10A, at 334; thesecond would be opposite and typically a mirror image). The cartridge325, then, is configured to be installed in a housing with which sealarrangement 329 can be sealed, for example by projecting into a groovearrangement. Of course, seal arrangement 329 can be alternatelyconfigured. The particular seal arrangement 329 depicted, is configuredto form a radially directed seal; i.e., seal with sealing forces in oneor both of the general directions of double headed arrow 329 x; thedirections being generally orthogonal to air flow exiting a cartridge325 in the direction of outlet air flow direction arrow 329 y. Theparticular seal arrangement 329 depicted, is configured to at least forman outwardly directed seal, and can be configured to also form aninwardly directed radial seal; or, to alternately only form an inwardlydirected radial seal.

A second example cartridge is depicted generally at 340, FIG. 10B. Here,the media pack 300 has molded-in-place side pieces 342, 341, positionedover opposite ends 332, 333, FIG. 10. Seal member 343 is positioned(typically molded-in-place) to completely surround the media pack 300(including side pieces 340, 341). Seal member 343 is configured tooperate as a pinch seal, between air filter assembly components, toensure that air to be filtered must pass through the media pack 300before filtering. Such a seal can be analogous to the ones described inWO 2007/133635, published Nov. 22, 2007, the disclosure of which isincorporated herein by reference.

A third cartridge is depicted schematically in FIG. 10C at 350. Here,media pack 300 is positioned within a sheath 351, with oppositelypositioned (typically molded-in-place) side (end) pieces (only one ofwhich is shown at 352, the other being oppositely positioned).Molded-in-place side piece 352 includes an aperture 354 therethrough,around which is provided a seal arrangement 355. This will be aconstruction generally analogous to those described in U.S. provisionalapplication 61/130,790, filed Jun. 2, 2008, the complete disclosure ofwhich is incorporated herein by reference. The particular sealarrangement 355 depicted, is configured for formation of a radial sealwith a portion of an air filter assembly.

Of course, the same principles and variations can be applied, even ifthe media pack 300 is fanned or otherwise modified to a differentarcuate shape. An example is shown in FIG. 11, in which the media pack300 is fanned to a semi-circular shape; i.e., a 180° internal arc.Referring to FIG. 11, cartridge 300 is positioned in extension betweenends pieces 357, 358, which are positioned to close end of the strips. Apinch seal analogous to pinch seal 343, FIG. 10B, could be positioned onthe arrangement 359, of FIG. 11. Of course media pack 300 fanned into asemicircular shape, could be incorporated with a cartridge usingalternate seal arrangements, for example analogous to those depicted inFIGS. 10A and 10B.

It is noted, of course, that the number of strips within in a stack orstack section may be varied, depending upon how large an arch, and thespecific shape of the arch, over which the media pack (or media packportion) is to be shaped, for example fanned. By using the samereference numeral, 300, for various media packs characterized herein, itis not meant that each identified media pack has the same number ofstrips.

Another example air filter cartridge is depicted in FIGS. 12-13.Referring to FIG. 12, cartridge 380 is depicted as comprising a mediapack 381. The particular media pack 381 comprises a stack 300 fannedinto an arcuate closed loop shape which extends completely around a 360°arc. Referring to FIG. 12, assume for purposes of example, that strips383, 384 comprise the top and bottom strips of the stack 300 beforefanning into the arcuate shape 381. Adjacent inner edge 386, of thestack 300, a bead of sealant can be provided between strips 383, 384, toensure the end strips 383, 384 do not define a leak path therebetweenfor air to be filtered, by cartridge 380. A media pack, 381, configuredin a closed loop orientation, such as that in FIG. 12, is characterizedas comprising media stack 300 fanned in an arcuate shape around thecentral, open, filter interior 388. There is no specific requirementthat the “closed loop” of a closed loop configuration be defined ascircular arc, and alternate configurations are possible.

Still referring to FIG. 12, opposite ends 332, 333, of the fanned mediapack 300 are shown sealed to, or potted to, opposite end pieces 390,391. In the particular example depicted, end piece 390 has a centralaperture 395 therethrough, in communication with open central volume388. End piece 390 includes a housing seal arrangement or member 396thereon, which surrounds aperture 395. Seal member 396 can be pressed,axially, against a surface of an air filter assembly, to seal cartridge380 around a clean air outlet. Thus, herein, seal member 396 willsometimes be referred to as a “housing axial seal” or by similar terms.

In some applications, for the particular configuration depicted in FIG.12, of cartridge 380, end piece 391 would be closed, i.e., it would notinclude an aperture analogous to aperture 365 therethrough. In someapplications, end piece 391 could be provided with an aperture analogousto aperture 395 therethrough, and also with a seal analogous to seal396. For such an example, when cartridge 380 is used, the centralaperture in end piece 391 would need to be closed, for example by apressure plate or analogous structure.

It is noted that the example cartridge 380, depicted relies upon asealing forces directed “axially.” By the term “axial” and variantsthereof in this context, reference is meant to sealing pressure in ageneral direction of a central longitudinal axis through open centralvolume 388 in a direction between end pieces 391, 390.

By comparison to a typical fluted media, typical media strips 301 canprovide a cylindrical media pack 399, which is somewhat stronger in theaxial direction. This in part results from the adhering of the flutedsheet to the facing sheet, in individual strips 301. The strength may beincreased even further, if, adjacent the stream ends 300 x, theindividual strips are darted in accord with FIG. 5, or are otherwisepressed or crushed against one another, forming a strong, stiff, edgeseam in each strip 301.

As a result, in some example applications, cartridge 380 may be usedwithout further structure therein, to provide axial strength to thecartridge 380. On the other hand, in some example applications, it maybe desirable to provide an expanded metal liner or other perforatesupport member, against either or both of inner, or downstream, face 300i and the outer, or upstream, face 300 x. Such supports will provide forshape retention, as well as increasing axial strength (againstdeformation or collapse of cartridge 380).

It is also noted that by comparison to a cylindrical media pack ofpleated paper, a cylindrical media pack comprising a fanned stack ofsingle facer strips can be configured to advantage with a relativelylong media depth. That is, ordinary pleated media is somewhat limitedwith respect to the depth of pleats that can be formed, due to pleatcollapse masking media inhibiting air flow. When media depth comprises asingle facer strip of fluted media secured to the facing media,relatively long media depths, outside edge to inside edge can be formed.Thus with arrangements in accord with the descriptions herewith, avariety of media pack depths are possible. Indeed depths (distance fromupstream edge to downstream edge in the various strips) on the order of4-12 inches (10.1-30.5 cm) can be accommodated.

In FIG. 13, a schematic side elevational view of cartridge 380 isdepicted.

In FIG. 14, a schematic top plan view of cartridge 380 is depicted.

Still referring to FIGS. 12-14, it is noted that the particular mediapack 300 depicted, being a cylindrical configuration, requires that themedia pack 300 be formed in a typical manufacturing operation into astack, which is then be fanned into the full 360° loop orientation,while a final sealant bead is positioned adjacent edge 300 i. It will,in some instances, it may be desirable to use for the particular sealantbead in cartridge 380, described above as being between layers 383, 384,a material which will set relatively quickly, to inhibit media pack 300from collapsing out of the cylindrical shape. Also it will be desirable,in some instances, during manufacture, to provide a support to retainthe media pack 300 in the closed loop orientation, as the sealant beadbetween the end layers 383, 384 sets.

IV. Example Filter Assembly and Cartridges Therefor, FIGS. 15-26

Filter cartridges of the type generally described herein above, can beapplied in a variety of fluid filter assemblies. Herein, example airfilter assemblies are depicted. The term “air filter assembly” isgenerally meant to refer to an assembly configured for directing air tobe filtered therethrough, with passage through one or more air filtercartridges. Air filter assemblies can used in a variety of applications.Air filter assemblies that are used to filter engine intake air forinternal combustion engines as used in vehicles and other equipment, aresometimes referred to as air cleaner assemblies. Air filter assembliesthat are used for filtering air from industrial processes, are sometimesreferred to as dust collectors or by similar terms. Air filterassemblies are also used for air intake to gas turbine systems. Also,cabin air filters are air filter assemblies are used for filtering airin aircraft and vehicle (or equipment) cabins. The term “air filterassembly” as used herein generally, as not meant to indicate a specificapplication for air filtering, without further characterization.

In FIGS. 15-29, an air filter assembly and components therefor,configured to use a fanned or arcuate media pack generally in accordwith the principles discussed above for media pack 320, are depicted.Specifically in FIGS. 15-17, filter cartridge 400 for use in an airfilter assembly 401, (FIGS. 18-29) is depicted.

Attention is first directed to cartridge 400, FIGS. 15-17.

Referring first to FIG. 15, cartridge 400 generally comprises a mediapack 405 extending between end pieces 406, 407. Media pack 405 generallycomprises an arcuate media pack corresponding generally to media pack300, fanned into a closed loop (arcuate) configuration 408. Thus mediapack 405 comprises a plurality of single facer strips (301, FIG. 7) eachcomprising a fluted sheet secured to a facing sheet, and fanned around a360 degree arc, to form a closed loop. The particular configuration ofmedia pack 405, FIG. 15, is to an oval (in this example elliptical)shape, having opposite narrow, carved, ends 405 a, 405 b, and morewidely arcuate opposite sides 405 c, 405 d.

It is noted that herein when it is said that media pack 300 is used incartridge 405, reference is meant to the media pack generally. Thespecific number of layers, i.e. single facer sheets or strips, can bemodified to accommodate the particular volume and shape desired.

In general, media pack 405 is configured for the fanning to surround anopen central interior 488, which will generally comprise a clean airvolume when cartridge 400 is used.

Still referring to FIG. 15, end pieces 406, 407 are positioned overopposite sides 412, 413 of media pack 405. For the particular exampledepicted, the end pieces 406, 407 can be molded-in-place, for examplefrom a hard urethane, or can comprise metal or preformed plastic pieces,secured to the media pack 405 with potting.

Still referring to FIG. 15, end piece 406 has a central aperture 420therethrough, providing air flow communication with an open interior488. For the example cartridge 400 depicted, end piece 407 includes anaperture analogous to aperture 420 therethrough.

For the particular example cartridge 400 depicted in FIG. 15, aperture420 has an oval shape, a specific example an elliptical shape. In atypical arrangement, the elliptical shaped aperture 420 would have alength ratio of longest axis-to-shortest axis, within the range of about2.1 to 1.3, inclusive, although alternatives are possible.

Surrounding aperture 420, on end piece 406, is provided seal member 421.An analogous seal member 422, FIG. 17 is provided on end piece 407.

As a result of the above described instruction, cartridge 400 hasopposite ends corresponding to end pieces 406, 407 which are the same.Thus, the cartridge 400 can be mounted in either of two orientations.This will be apparent from discussions below with respect to assembly401.

As previously described with respect to FIGS. 12-14, the media pack 405of cartridge 400 can be provided with either or both of an inner linerinside region 488 adjacent the media pack 405, and an outer liner aroundouter surface 405 x, to provide support to the media pack 405 and/oraxial strength to cartridge 400. For example, an expanded metal liner orplastic mesh can be used.

In FIG. 16, a top plan view of cartridge 400 is depicted, and the shapeof aperture 420 and seal member 421 can be seen.

In FIG. 17, a side elevational view of cartridge 400 is depicted, takengenerally toward side 405 c. Here end piece 407 can be depicted, withseal member 422, analogous to seal member 421, thereon.

It is noted that in some applications, end piece 407 could be closed,i.e., not have a central aperture therethrough.

A variety of specific dimensions for the cartridge 400 are possible. Insome typical applications, the cartridge will have a ratio of longestcross-sectional axis-to-shortest cross-sectional axis within the rangeof about 1.1-1.8, typically 1.1-1.4, although alternatives are possible.In a particular example system, the media pack longer cross-sectionaldimension is 25.97 inches (66 cm) and has a narrower cross-sectionalwidth, orthogonal to the longer cross-sectional width, of about 18.26inches (46.4 cm). An example length of the media pack would be about 26inches (66 cm).

Attention is now directed to FIG. 18, which an air filter assembly 401is depicted, configured, for example, for use with one or more airfilter cartridges as generally characterized herein; i.e. which includea media pack comprising an arcuate, fanned, arrangement of single facerstrips; each single facer strip comprising fluted media secured tofacing media. The particular air filter assembly 401 depicted, is a dustcollector for an industrial process. However, the features andcharacteristics described, can be used in air filter assemblies foralternate purposes.

Referring to FIG. 18, the particular air filter assembly 401 depicted,is of a type generally characterized herein as a reverse pulse airfilter assembly 499. By the term “reverse pulse” air filter assembly andvariants thereof, as used herein, it is meant that the air filterassembly 401 is configured so that one or more (selected) pulse jets ofgas (typically air) can be directed through an operably installed airfilter cartridge in a direction opposite to a direction of normal airflow during filtering. This effect allows for periodic cleaning of dustfrom the filter cartridge, regenerating the filter cartridge forcontinued filtering. This process can extend the lifetime of the filtercartridge use, before servicing; i.e. before replacement. In someinstances “reverse pulse” air filter assemblies and features will alsobe characterized herein as “pulse jet” air filter assemblies andfeatures, or by similar terms.

In general, pulse jet air cleaners with alternate filter cartridges areknown; see for example WO 2006/105438, published Oct. 5, 2006; U.S. Pat.No. 6,488,746; and, WO 2007/149388, published Dec. 27, 2007; each ofwhich is incorporated herein by reference. It is noted that many of thereverse pulse cleaning techniques described in these references can beincorporated in a reverse pulse jet air cleaner 499 including one ormore filter cartridges with media packs as characterized herein.

It is also noted that the media of the filter cartridge in assembly 401,comprises single facer media (fluted sheet secured to facing sheet). Itis advantageous for reverse pulse operation, for the media pack to befanned at the inlet flow face. This means that as the reverse pulsecleaning jet, which extends into the outlet flow face of the media pack,leaves the media pack along the inlet flow face, it will help move dustin an efficient manner from the cartridge.

Still referring to FIG. 18, again the particular reverse pulse or pulsejet air filter assembly 499 depicted, is an industrial dust collector500. Thus, the particular air filter assembly 401 depicted, isconfigured to be positioned in association with an industrial site orprocess, to filter air from the process, for removal of contaminant, forexample, particulate comprising dust and related materials.

Referring to FIG. 18, in general terms, air filter assembly 401comprises a housing 505 including a housing body 506 and access cover507. The access cover 507 is positioned over an end 506 e, of thehousing body 506. The access cover 507 is configured to open housing end506 e, for service access to an interior of housing 505.

A variety of alternate configurations for the access cover 507 arepossible. The particular access cover 507 depicted, comprises a door 507d, which is hingedly mounted and which can be opened by turning oflatches 509. It is noted that in alternative applications of thetechniques according to the present disclosure, the access cover 507 canbe configured to be completely removed from housing body 506 whenopened.

Still referring to FIG. 18, air filter assembly 401 generally includesan air flow inlet arrangement 510 and an air flow outlet arrangement511. Air to be filtered generally enters housing 505 through air flowinlet arrangement 510. Filtered air from the air cleaner assembly 401,is removed via air flow outlet 511.

Still referring to FIG. 18, the housing 505 includes a mounting padarrangement 515 thereon. The mounting pad arrangement 515 allows thehousing 505 to be positioned appropriately for use. The particularmounting pad arrangement 515 comprises a plurality of legs 516 and feet517 with interconnecting braces 518.

The air filter assembly 401 further includes a dust ejection assembly520, with a dust outlet 521.

In general terms, when the air cleaner assembly 401 is operated withreverse pulsing, at least a portion of dust which is dislodged from anenclosed filter cartridge, eventually falls into dust ejector assembly520. This dust can be removed from the ejector assembly 520 through thedust outlet 521, and be directed, for example, into a bin, not depicted.

Generally, during an operation of filter assembly 401, dust outlet 521will be closed. A variety of arrangements to close dust outlet 521 canbe used including: a hose and drum collector arrangement; attachment toa screw conveyor or other mechanism for moving dust; or, providing aslide gate or air lock in association with outlet 521. In general terms,what is desired is that during operation, unfiltered air is not drawninto assembly 401 through dust outlet 521.

Attention is now directed to FIG. 19. Selected features alreadycharacterized are generally indicated by like reference numerals. InFIG. 19, pulse jet cleaning assembly 530 is depicted, comprising acharge tank 531 and a plurality of pulse jet valves 532. In generalterms, the charge tank 531 is positioned to be periodically charged witha compressed gas, for example air, to be used for the pulse jet cleaningoperation. Pulse jet valves 532 are positioned to receive compressed gasfrom the charge tank 531 and to be operated (for example controlled by asolenoid switch arrangement) to selectively direct a pulse jets of gasinto housing 505, directed in a desirable manner, as discussed below, toprovide pulse jet cleaning of one or more enclosed filter cartridges. Itis noted that the charge tank 531 can be attached via compressed airlines to a compressed air source, such as a remote tank or compressorsystem. A nozzle 535 for such a connection is shown. It is also notedthat the air filter assembly 401 can be provided with a variety ofelectronic systems, for control of the pulse jet valves 532, as desired.

Attention is now directed to FIG. 20. Here air filter assembly 401 isdepicted, with access cover 507 opened. That is, latches 509 have beenrotated to allow access cover 507 to pivot around hinge arrangement 540,opening an access aperture 541 at end 506 e of housing body 506 forservice access to an interior 505 i of housing 505.

Still referring to FIG. 20, it is noted that the particular housing 505depicted is configured to receive, operably installed therein, twofilter cartridges 400 a, 400 b, in the example shown each generallycorresponding to filter cartridge 400, FIGS. 15-17. It is noted thatalternate configurations for the housing 505, to receive an alternatenumber of, or shape of, cartridges, is possible.

Referring to FIG. 20, it is noted that the air cleaner assembly 401 isdepicted in partial exploded view, with one of the cartridges 400, inparticular cartridge 400 b, shown in exploded view, i.e. as it generallywould appear either during mounting or dismounting.

Referring to FIG. 20, mounted inside of housing 505, adjacent inletarrangement 510, is depicted deflector plate arrangement 545. Thedeflector plate arrangement 545 is positioned as a baffle so that inletair passing into interior 505 from inlet arrangement 510 is divertedfrom direct impingement on cartridge 400 a. Rather, the air is forced tobecome distributed within in interior 505 i, to help with more evendistribution of dust loading of the two cartridges 400 a, 400 b.Deflector plate 545, then, in general comprises an inlet baffle orshield 545 a.

Still referring to FIG. 21, each cartridge 400 a, 400 b is mounted overa separate cartridge support or yoke 550. In FIG. 20, the particularcartridge support or yoke 550 b, for cartridge 400 b is depicted. Ofcourse, an analogous cartridge support or yoke (550 a) would bepositioned with cartridge 400 a mounted thereover.

Attention is now directed to FIG. 22, a fragmentary view of a selectedportion of FIG. 20, in which cartridge support or yoke 550 b is depictedin greater detail.

Referring to FIG. 22, cartridge support 550 b includes arcuate cartridgeengagement members 551. These arcuate cartridge engagement members 551are configured to engage interior surfaces of apertures (such asaperture 420) in end pieces 406, 407 of cartridge 400 b. This willsupport the cartridge 400 b over the cartridge support or yoke 550 b.

Cartridge support or yoke 550 b is positioned so that when cartridge 400b is positioned thereover, an outlet aperture, corresponding to aperture420, FIG. 16, for cartridge 400 b is aligned for air flow exit throughair flow outlet arrangement 560. Air flow outlet arrangement 560, forthe example depicted, comprises a pair of apertures 560 x, 560 y,through tube sheet or wall 561. The outlet arrangement 560 is configuredso that air flow exiting cartridge 400 b through outlet aperture 420,FIG. 16 can pass through the apertures 560 x, 560 y, and into a cleanair plenum. From there, the air can reach air flow outlet arrangement511 and exit housing 505. Such an alignment between filter cartridge 400and an air flow aperture or outlet arrangement 560 will sometimes bereferred to herein as “air flow communication” or by similar terms.

Still referring to FIG. 22, it is noted that cartridge support or yoke550 includes a center yoke member 565. The center yoke member 565includes threaded end 566, remote from wall 561. Referring to FIG. 20,when cartridge 400 b is mounted over yoke 565; end 566 will projectthrough cartridge 400 b. Seal (pressure) plate 570, FIG. 20, ispositioned over threaded end 566, with the threaded end projectingthrough central aperture 571. Nut 572 and washer 573 can be positionedover end 566, pressing plate 570 in place. In general, this will lead toa sealing of aperture 420 x, FIG. 20, by compressing plate 570 againstseal member 422. Further, a corresponding seal member 421, on anopposite end of cartridge 400 b corresponding to seal member 421, FIG.16, will press against wall 561, providing for an axial sealing ofcartridge 400 b in place, with each opposite axial seal 421, 422 beingcompressed into sealing engagement with housing structure. This willensure that air flow, to reach outlet aperture arrangement 560, FIG. 22,must pass through cartridge 400 b.

An analogous mounting arrangement, with a corresponding cartridgesupport 550 and analogous features, with an analogous seal plate 570 andnut 572, is provided for cartridge 400 a.

Referring again to FIG. 22, the particular cartridge support or yoke 550depicted, includes a vane arrangement 575, comprising a first pair ofvanes 576 a, 576 b forming, a first cross vane 576; and, a second pairof vanes, 577 a, 577 b forming second cross vane 577. The vanearrangement 575 is configured to facilitate a pulse jet cleaningoperation of cartridge 400 b. For the particular assembly depicted,cross vane 577 is orthogonal to cross vane 576.

Referring to FIG. 22, first cross vane 576 is impermeable, i.e. it doesnot include apertures therethrough, and is orientated to extend acrossinterior 488 of cartridge 400 b, in a direction corresponding to theshorter axis of the oval (elliptical) interior 488. The second crossmember 577 is not solid, i.e. is not closed, but rather is permeableincludes an aperture arrangement 580 therethrough, in the exampledepicted comprising a plurality of apertures. The second cross vane 577,with apertures 580 therethrough, is configured to extend across interior488 of cartridge 400 b in a direction generally corresponding to alonger axis of the oval (elliptical) interior 488.

Referring to FIG. 22, it is noted that the first cross vane 576, whichis generally imperforate, i.e. solid, is positioned between air flowexit apertures 560 x, 560 y. As will be understood from detaileddescription below, during a pulse jet cleaning operation, apertures 560x, 560 y operate as pulse jet entrances into interior 488 of cartridge400 b. First cross vane 576, then, being imperforate allows for ageneral separation of the effects of pulses through apertures 560 x and560 y.

On the other hand, aperture arrangements 580, allow for the distributionof pulse entering aperture 560 x, across the interior 488 of cartridge400 b, in a half of that interior at (i.e., to one side of) impermeablevane 576. An analogous effect is also provided for aperture 560 y, foran opposite half of interior 488.

In general terms, the typical cartridge support or yoke 550, withrespect to each cartridge is configured for one or more of thefollowing:

-   -   (a) It will support the associated cartridge, when positioned        thereover, centered over outlet arrangement 560.    -   (b) It includes yoke arrangement 565 for engagement with a seal        plate, to provide for a sealing of the cartridge 400 in        position.    -   (c) It also includes an internal vane arrangement for allowing        air flow exit through two apertures, 560 x, 560 y, of outlet        arrangement 560, while generally separates reverse pulse flow        into the cartridge, through apertures 560 x, 560 y, with respect        to which portions of the cartridge 400 are maximally effected.

It is noted that an analogous effect can be accomplished with ananalogous cartridge support 550 associated with cartridge 400 a, FIG.20.

Indeed, attention is now directed to FIG. 21, in which a seal plate 570(570 a), for cartridge 400 a is shown removed, and a cartridge support550 (550 a) is shown positioned within an interior 488 of cartridge 400a.

Attention is now directed to FIG. 23, a side elevational view of airfilter assembly 401, depicted generally toward a side having accesscover 507 thereon. Selected features as previously characterized aregenerally viewable.

In FIG. 24, a cross-sectional view taken generally along line 24-24,FIG. 23, is provided. Referring to FIG. 24, the cartridges 400,corresponding to cartridges 400 a, 400 b, are shown mounted overcartridge supports or yokes 550.

Referring first to cartridge 400 b, it can be seen that positioned withinterior 505 i, of housing 505, two venturi members 585 x, 585 y arepositioned on wall 561, in association with cartridge 400 b. Venturimembers 585 x, 585 y are positioned with one each associated with eachof apertures 560 x, 560 y, respectively. It is noted that in FIG. 24, inreference to cartridge 400 b, yoke apertures 580 can be seen.

In general, referring to FIG. 24, within housing 505, region 500 x is adirty air region and region 500 y is a clean air region or clean airplenum. Referring specifically to the operation of cartridge 400 b, asair laden with dust enters the housing 505 through inlet arrangement510, the air will distribute dust on cartridge 400 b as it passestherethrough, into interior 488. This air will then exit cartridge 400 bthrough apertures in wall 561, those apertures corresponding toapertures 560 x, 560 y, FIG. 22. This air will pass through venturimembers 585 x, 585 y and into clean air plenum 500 y. The filtered airthen exits housing 505 through outlet arrangement 511. (Cartridge 400 aoperates analogously.)

Periodically, when pulse jet cleaning is desired, a selected pulse jetof gas from pulse jet valves 532 will occur. In particular, attention isdirected to pulse jet valves 532 x, 532 y. Pulse jet valve 532 x ispositioned to direct the pulse jet of air from charge tank 531 throughclean air plenum 500 y into venturi member 585 x. This pulse jet willthen pass through pass through wall 561 (i.e. through aperture 565 x,FIG. 22) and into interior 488 of cartridge 400 b. First cross vane 576will generally keep the distribution of this pulse gas jet from valve532 x in an upper half of cartridge 400, FIG. 24. Apertures 580 insecond cross vane 577 and in particular in an upper half thereof, willallow a pulse from pulse jet valve 532 x, to distribute across the upperhalf of cartridge 400 b, driving the pulse through the media pack 405,and dislodging dust collected in the media 405 therefrom. The dust willeventually fall into dust ejection assembly 520, and in due coursethrough outlet 521.

Analogously, pulse jet valve 532 y is positioned to direct a pulse jetof gas from charge tank 531 through venturi member 585 y and into aninterior 410 of cartridge 400 b, to dislodge dust from a lower half ofcartridge 400 b.

Operation of valves 532 x, 530 y can be simultaneous or sequential, asthe circumstances permit. It is generally considered that a sequentialoperation with upper valve 532 x operated before the lower valve 532 ywill be desirable, for gravity assistance in moving dust from cartridge400 b eventually into dust ejection arrangement 520. Multiple pulses canbe used.

Various pressures in charge tank 531, and various lengths and pulses canbe used. Typically, the pressure within charge tank 531, i.e. thepressure of a pulse, will be about 90 psi; and, the length of a pulsewill be about 0.1 second, although alternatives are possible.

Referring to FIG. 24, upper cartridge 400 a is analogously associatedwith two venturi members 585 a, 585 b and two pulse jet valves 532 a,532 b.

Still referring to FIG. 24, it is noted that each of the pulse jetvalves 532 a, 532 b, 532 x, 532 y is provided in association with apulse director 533. The pulse directors 533, sometimes referred to aspulse direction members, or as a pulse jet flow direction arrangement,are tubes configured to selectively direct a pulse jet of air from theassociated pulse jet valve, into the associated venturi member. Hereinin some instances the combination of a pulse jet valve and a pulse jetdirector, will be referred to as a pulse jet valve/pulse direction (orpulse director) assembly or combination.

The particular sequence of operation of pulse jet valves of a pulse jetcleaning system, is matter of choice for desirable effects. For anarrangement in accord with FIG. 24, in which two cartridges 400 a, 400 bare positioned interiorly, with one above the other, it is generallyexpected that a sequential pulse from the upper most valve 532 a to thelower most pulse valve 532 y will be preferable, again to obtain somegravity assistance in moving the dust from the cartridges 400 a, 400 bdownwardly, into the dust ejection arrangement 520.

Attention is now directed to FIG. 25, a cross-sectional taken along line25-25, FIG. 23. Here, the cross-section is taken such that thecartridges 400 a, 400 b are not shown in cross-section. Each can be seensecured in place by seal plate 570 and nut 572.

In FIG. 26, an enlarged fragmentary view of a selected portion of FIG.25 is viewable. In particular, in FIG. 26, wall 561 comprising tubesheet 561 x, is shown with venturi members 585 a, 585 b, 585 x, 485 y onone side thereof, and with cartridges 400 a, 400 b on an opposite sidethereof, comprising cartridges 400 a, 400 b secured in place by sealplates 570 and nuts 572. It can be seen that each cartridge 400 a, 400b, is associated with two venturi members; cartridge 400 a is associatedwith venturi members 585 a, 585 b; and, cartridge 400 b is associatedwith venturi members 585 x, 585 y. This allows for a selected pulsingfrom a pulse jet assembly described above in connection with FIGS. 24and 25, to be configured such that one venturi member is associated witheach half of a cartridge 400; and, one pulse jet valve is associatedwith each venturi member. This can provide for an efficient cleaningoperation of the cartridges 400. For the particular assembly depicted,use of two venturi members, and thus two pulse jet valves associatedwith each cartridge 400 is facilitated by the oval (in the exampleelliptical) shape.

It is noted that in alternate applications of the techniques describedherein, assemblies will be configured in which only venturi member isassociated with each cartridge, or which more than two venturi membersare associated with a selected cartridge.

Attention is now directed to FIG. 27. In FIG. 27, a view of thestructure depicted in FIG. 26 is shown, generally directed toward theventuri arrangement 585. Here, one can see through the individualventuri members (585 a; 585 b; 585 x; and, 585 y) and thus through thewall 561 and into the interiors 488 of the two cartridges 400 a, 400 b,positioned on the opposite side of the wall 561. In the particular viewof FIG. 27, one can see the vertical or second cross vane 577 positionedwithin an interior of each of the cartridges 400 a, 400 b.

In FIG. 28, a perspective view is provided of selected structure on theopposite side of the wall 561 from the side viewable in FIG. 27.Referring to FIG. 20, cartridge 400 b can be seen positioned overcartridge support or yoke 550. Here, alignment with the two apertures560 x, 560 y can be seen. Other features viewable in FIG. 28 aregenerally as previously described.

Finally, in FIG. 29, an enlarged view of a selected portion of FIG. 27is depicted. This view can generally can be considered opposite thatviewable in FIG. 28, with a portion of wall 561 also being shown.Referring to FIG. 29, it is noted that cartridge support 550 can beviewed in an interior of cartridge 400 b, with vane arrangement 575viewable, having impermeable or solid first, horizontal, cross vane 576and permeable, second, in this instance, vertical cross vane 577. Thetwo venturi members 585 x, 585 y are also viewable.

For the particular assembly 401 depicted, i.e. an industrial dustcollector, the DCI A flute, Table A, can be used for the corrugatedsheet in the single facer strips, although alternatives are possible.

In general terms, an example air filter assembly includes at least oneair filter cartridge therein. Typically, each air filter cartridge isassociated with a venturi arrangement or assembly, within the housing,positioned to help direct air flow from the filter cartridge into aclean air plenum of the housing. For an example system depicted, usingoval shaped filter cartridges, each filter cartridge is associated withat least two venturi members, and in a specific example, two venturimembers only. A pulse jet air cleaning assembly is provided, having atleast one pulse jet valve/pulse direction arrangement associated witheach filter cartridge, and in a particular example depicted, two withrespect to each filter cartridge. A variety of alternate applications ofthe techniques will be understood, given the above characterizations.

V. Alternate Media Pack Configurations, FIGS. 30 and 31

The media pack arrangements characterized herein above are generallydepicted as configured formed from a media pack comprising a stack ofsingle facer strips configured with ends opposite a stacking bead spreadapart somewhat. That is, in each example arrangement, the media pack canbe characterized as having flow faces, one being an inlet flow inletface and the other being an outlet flow face; and, the stacking bead ispositioned adjacent one of the flow faces (i.e. closer to one of theflow faces than the other). Fanning can occur by spreading apart layersof the stack, adjacent a flow face opposite the one having the stackingbead adjacent thereto.

In contrast, in Figs. FIGS. 30 and 31, principles are analogouslyapplied in which the arcuate shape is made by providing an inside arc,to the stack of single facer strips, by compressing the strips towardone another, and with the outside arc being adjacent the stacking bead.Again, herein the term “inside arc” and variants thereof, is meant torefer to the flow face portion with the shorter arc (concave surface),and the outside arc is meant to refer to the arcuate portion of the facewhich has the larger arc (convex surface).

Referring to FIG. 30, an example filter cartridge comprising such amedia pack is depicted generally, at 700. The cartridge 700 depicted hasa generally cylindrical configuration for the media pack 701, althoughalternatives are possible. The particular cartridge 700 depictedcomprises a media pack 701 extending between first and second end capsor end pieces 703, 704. Although a variety of end piece configurationsare possible, the particular end pieces 703, 704 depicted are generallymolded-in-place, for example from foamed polyurethane. In alternateapplications of the principles described herein, one or more of the endpieces 703, 704 can be preformed, for example from a hard plastic ormetal, and be potted in place by adhesive/sealant.

A variety of configurations are possible. In the example cartridge 700,FIG. 30, end piece 704 is closed, i.e. has no central aperturetherethrough. End piece 703, on the other hand, is open, having acentral aperture 708 therein.

The cartridge 700, as thus far characterized, as generally analogous tocartridge 380, FIG. 12. An analogous housing seal could be used forcartridge 700, to housing seal arrangement 396, FIG. 12; such anoptional axial seal being shown at 707. However, for the examplecartridge 700 depicted, aperture 708 is lined by a framework or housingradial seal member 709, configured to seal around an outlet tube orsimilar construction with radially directed forces (i.e. toward or awayfrom a central axis of media pack 701). Herein, a seal arrangementhaving sealing forces directed toward or away from a central axis of amedia pack, are generally characterized as a “radial seal” or by similarterms; the particular seal 708 depicted, being an inwardly directedradial seal. Herein, a seal arrangement such as 396, FIG. 12, which issealed by compression forces in the general direction of a central axisfor the cartridge, will be referred to as an “axial seal” or by varioussimilar terms.

In use, air flow would be in the general direction of arrow 715, for airto be filtered. The air would pass through the media pack 701 into openinterior 716, and then the filtered air could leave the cartridge 700through aperture 708.

In the terms used above, the internal arc of the media pack 701 will bealong the interior 716, or concave side, as indicated generally at 717,and the exterior arc will be along an outer surface 718 (or convex side)as indicated generally by arc 719.

Attention is now directed to FIG. 31, a schematic cross-sectional viewtaken generally along line 31-31, FIG. 30.

FIG. 31 is a schematic depiction of a portion of the media pack 701. Theportion 701 a depicted, shows, schematically, four (4) single facerstrips 720, 721, 722 and 723. Referring to strip 720, as an example, thestrip 720 comprises a corrugated sheet 720 c and a facing (in thisinstance flat) sheet 720 f secured to one another. Adjacent end 720 e,the corrugated sheet 720 has been darted, folded or otherwise compressedclosed.

Each of the single facer strips 720, 721, 722, 723 would have a similarconstruction. Between each adjacent two single facer strips, is provideda stacking bead 725. The stacking bead 725 provides for prevention ofexterior air flow, unfiltered, extending through the media pack betweenthe single facer strips.

Filtering air flow would generally be into an interior 720 i, 721 i, 722i and 723 i of each of the strips 720-723, respectively, along arc 719.The darted or compressed ends (corresponding to end 720 e) means thatthe air will exit those flutes by filtering passage through media, intothe region between the single facer 720-723, downstream from the sealingbeads 725. The filtered air will exit the media pack in the generaldirection shown by arrow 730. Thus, for the example shown, filtering airflow is from the exterior arc 719 to the interior 717.

Referring to FIGS. 30 and 31, it is apparent that the “fanning” in thisinstance is with the ends of the single facer strips adjacent the outeror exterior arc 719 spread apart, and with the ends adjacent theinterior arc 717 pressed together. Further, the ends that are spreadapart are generally those adjacent the stacking beads 725. This, then,leads to a different media pack configuration than is shown in theexample of FIG. 12, where the stacking bead was adjacent the interiorarc, and with the opposite outer ends spread apart.

From review of FIGS. 30 and 31, it will be understood that the term“fanned” as used herein in connection with identified characteristics ofthe media pack 701, is meant to refer to a media pack in which one ofthe end of the strips (inlet or outlet) is spread apart relative to theopposite end of the strips. There is no specific requirement, unlessotherwise stated, that this “spreading apart” occurs from actualphysical pulling apart of the layers. It could occur, for example, bypressing the layers together adjacent the opposite end.

Thus, in the general terms used herein, media pack 701 includes aplurality of single facer strips positioned in a stack defining oppositeends and flow surfaces, 716 and 718 respectively. Each one of the singlefacer strips in the stack comprises a sheet of fluted media secured to asheet of facing bead. A stacking bead at 725 is provided betweenadjacent single facer strips. The stack includes at least a firstportion (in the example depicted, the entire stack) configured in anarcuate configuration of individual single facer strips oriented withrespect to one another to form an arcuate configuration. The media packis closed to passage of unfiltered air completely therethrough, thisbeing provided by a combination of the stacking beads 725 and the closedend 728.

VI. Selected Configurations Using a Fanned, Slanted Stack, Media Pack,FIGS. 32-45

It is noted that selected fanned media pack configurations, havingarcuate sections, in a media pack or media pack that is comprised of oneor more stacks of single facer media as characterized herein, can beconfigured from one or more slanted stacks. This will be understood byreference to FIGS. 32-45.

Attention is first directed to FIG. 32, in which a slanted stack 800 isdepicted schematically. Referring to FIG. 32, stack 800 is generallyanalogous to stack 201, FIG. 6, except as described. The stack 800comprises a plurality of layers 801, depicted schematically, each ofwhich comprises a single facer strip. The strips 801 have a first inletend, thus defining inlet face 802 and a second outlet end defining anopposite outlet face 803. As a result, filtering air flow through theslanted stack 800 is, for the example depicted, in the general directionof arrows 805, although an alternate, opposite flow pattern is possible.

A difference between the slanted stack media pack 800, FIG. 32 and the“blocked” stacked arrangement 201, FIG. 26 is that in slanted stack 800,FIG. 32, while the opposite inlet and outlet flow faces 802, 803 areparallel to one another, they are not perpendicular to all adjacentsides; i.e. to opposite top and bottom 800 x, 800 u, and to oppositesides 800 s. This results from having adjacent single facer stripsoffset from one another toward one of the flow faces. Stack 201, FIG. 6,a contrast, is typically referred to herein as a “blocked” stack, sinceeach pair of adjacent sides is configured to extend at right angles toone another, resulting from adjacent single facer strips not beingoffset from one another.

Still referring to FIG. 32, it is noted that the media pack can befanned apart, for example if a stacking bead is located adjacent face803, strips along face 802 can be fanned apart. Also, if the stackingbead adjacent face 803 is appropriately positioned, and the media packis appropriately long, adjacent face 802 the layers can be compressedtoward one another to create arcuate shapes.

It is also again noted that there is no specific requirement for the airflow pattern to be in the direction of arrow 805; i.e. it could oppositeto that direction as well.

An example filter cartridge configured from slanted stacked media packarrangements is depicted in FIGS. 33-43.

Attention is first directed to FIG. 33 in which a cartridge 820 isdepicted. Cartridge 820 generally comprises a media pack 821. The mediapack 821 comprises a z-filter configuration, and comprises a media pack821 having an arcuate, fanned, portion. Further, the media pack 821 isformed from at least one (in the example depicted two (2)) slantedstacks of media, generally corresponding to stack 800, FIG. 32.

Still referring to FIG. 33, the media pack 821 is positioned betweenfirst and second, opposite, side pieces 825, 826. The side pieces 825,826, close sides of the media pack 821. The side pieces 825, 826 can bemolded-in-place, or can comprise preforms secured to the media pack 821,with sealant adhesive. When preforms are used, the preforms can beformed from metal or plastic, for example. In the example arrangementdepicted, the sides 825, 826 can comprise plastic preforms to which themedia pack 821 is sealed and secured, for example by being potted withan adhesive, such as a polyurethane adhesive.

Still referring to FIG. 33, the cartridge 820 comprises an air flow exitaperture 830 providing for air flow passage between an interior 820 iand an exterior environment. Although air flow can be in eitherdirection, in a typical application it is expected that aperture 830will be an exit aperture for filtered air from interior 820 i.Surrounding aperture 830 is provided a framework or housing sealarrangement 831. The framework or housing seal arrangement 831 comprisesseal or gasket material surrounding the aperture 831 and oriented toform a seal against an air filter housing or other structure, in use.

As indicated above, although alternatives are possible, the particularcartridge 820 depicted, is configured for “out-to-in” flow duringfiltering. Thus, air to be filtered enters outer surface 8210 of mediapack, and exits inner surface 821 i, into interior 820 i. Filtered airthen exits aperture 830, and is directed on as intended by the equipmentwith which cartridge 820 would be used. Framework or housing sealarrangement 831 will prevent air from bypassing the cartridge 820 in thesystem of use.

In FIG. 34, a second schematic perspective view of the cartridge 820 isdepicted. Here, a fanned or arcuate portion 821 f of the media pack 821is depicted. This portion and its formation is described further hereinbelow.

In general, cartridge 820 will sometimes be referred to herein as havingan overall “arrow” or “arrow head” shape. By this it is meant that theoverall cartridge shape can be characterized as having a point or vertex820 v, FIG. 34, with sides 820 s diverging therefrom.

In FIG. 35, a top plan view of cartridge 820 is depicted. It is notedthat when installed in an air cleaner assembly, typically cartridge 820,when configured as shown, will be secured in place by frameworkappropriate to provide compression in the general direction of arrow 835so that framework or housing seal arrangement 831 is compressed againsta housing or tube sheet (i.e. framework) portion, around an exitaperture.

In FIG. 36 a side elevational view of cartridge 820 is depicted.

Referring again to FIG. 33, the cartridge 820 includes a pair of endpanels 840, 841 positioned adjacent opposite end 821 y, 821 x of themedia pack 821. The end panels 840, 841 are generally secured to themedia pack 821, and each preferably comprises an air impermeablestructure. The end panels 840, 841 as a result, inhibit bypass ofunfiltered air into interior 820 i. Further, for the particular assemblydepicted, the panels 840, 841 provide support for a section or portionof framework or housing seal arrangement 831 as described herein below.The panels 840, 841 can be preformed or be molded-in-place. In theexample, they are preformed.

Attention is now directed to FIG. 37, an exploded perspective view ofcartridge 820. Here, the opposite side pieces 825, 826 can be seenpositioned as mirror images of one another, along opposite sides 821 r,821 s respectively of media pack 821. In addition, end panels 841, 840can be seen adjacent ends 821 x, 821 y respectively.

Housing seal arrangement 831 is also viewable. It is noted that thehousing seal arrangement 831 could be preformed and be adhered to aremainder of cartridge 820, for example with adhesive, or it can beformed in place, i.e. molded-in-place. By the term “molded-in-place”, itis meant that the seal arrangement is molded onto the cartridge 820,instead of being preformed and then adhered with an adhesive or similarmaterial.

In FIG. 38, an alternate exploded perspective view of cartridge 820 isdepicted. Features previously described are viewable.

Referring to FIGS. 37 and 38, it is noted that the particular media pack821 depicted, is formed from two media pack stacks 821 m, 821 n, securedto one another along joint 821 j. For the particular example depicted,each of the sections 821 m, 821 n comprises: a fanned, slanted stacked,media section having an arcuate, fanned, portion. The specific exampleconfiguration of these sections 821 m, 821 n is described further hereinbelow.

In FIGS. 39-41, end panel 840 is depicted. It is noted that end panel841 can comprise an analogous, identical panel. Referring to FIG. 39,end panel 840 comprises a preform of metal or plastic shaped to include:end cover section 840 c, transition section 840 t and seal supportflange 840 f.

Comparing FIGS. 39 and 37, panel section 840 would generally be adheredto an end, for example, end 821 y, of the media pack 821 with anadhesive seal therebetween. The panel section 840 will be configured sothat seal support flange 840 f is appropriately positioned for mountingor positioning a portion of seal member 831 thereon.

A seal between the end 821 y of the media pack 821 and end corner orpanel 840 can be formed with a variety of adhesive of sealing materials,for example polyurethane can be used for this purpose.

In FIG. 40, a side elevational view of panel section 840 is depicted,and in FIG. 41 a plan view of panel section is viewable.

Again, section 841 can be an identical panel section to panel section840, if desired.

In FIGS. 42 and 43, media pack 821 is schematically depicted. In FIG. 42specifically, media pack 821 is viewable in perspective view, and inFIG. 43 in plan view.

It is noted that each of the views 42 and 43 is schematic, andindividual features of each single facer strip are not viewable

In general, referring to FIGS. 42 and 43, it can be seen that the twosides 821 m, 821 n are formed from separate media stacks, joined alongjoint 821 j. Also that for each of the sides 821 m, 821 n, the arcuate,fanned, configuration depicted, is formed from a slanted stack.

In FIGS. 44 and 45, one of the slanted stacks 821 n is viewable. It isnoted that the same stack can be used for section 821 m, if reversed orflipped over.

Referring to FIGS. 44 and 45, the panel section 821 n depicted, wouldtypically include a stacking bead adjacent the inner surface 821 i. Ineach figures, FIGS. 44, 45, arcuate, fanned, section 850 of the mediapack 821 n is viewable.

Still referring to FIGS. 44 and 45, it is noted that each media packsection 821 n (and by comparison media pack section 821 m) would includeopposite end faces 851, 852 when the media pack section 821 n is formedform a slanted stack as described herein above. One of faces 851, 852would typically be corrugated; the other one of faces 851, 852 wouldtypically comprise a flat sheet, although alternative constructions arepossible. Which one of the faces 851, 852 is corrugated and which one ofthe faces 851, 852 is flat, is a matter of choice and is not critical toincorporation of the stack of a media pack section 821 n into a mediapack 821 as described herein. Further, and referring to FIG. 42, whenthe two sections 821 n, 821 m are brought together, there is no specificrequirement that the joint 821 j be formed from one corrugated sheet andone flat sheet, two corrugated sheets, or two flat sheets. In any ofthese alternatives, an appropriate seal can be obtained by providing oneor more seal beads between the adjacent end faces of the two media packs821 n, 821 m.

It is noted that although alternatives are possible, typically at leasttwo seal beads will be used at the joint 821 j: a first, along interior821 i, positioned for example adjacent stacking beads within searchsection 821 n, 821 m; and, typically, a second along outer edge 821 z,FIG. 42. When this sealing bead 821 z, is used, flow cannot readilyenter joint 821 j between the two media packs 821 n, 821 m. Such a beadmay be desirable, for example, to prevent peeling apart of the mediapack 821 at this location.

VII. Some Additional Media Pack Configurations, FIGS. 46-48

From principles described herein above, it will be understood that awide variety of filter cartridges, with media pack configurationscomprising z-filter media oriented with arcuate sections, can be made,using principles according to the present disclosure. Within the arcuatesection, fanning can comprise spreading apart of layers along onearcuate face, or compression tighter of layers of one arcuate face.

In FIGS. 46-48, some additional variations are depicted.

Referring to FIG. 46, a media pack configuration is depicted generallyat 600. The media pack 600 is shown comprising z-filter media positionedas a closed loop in extension around an interior 601; the media pack 600being defined as having a first pair of opposite sides 603, 604; asecond pair of opposite sides 605, 606 and four arcuate corners 608;each corner 608, for example, comprising an arcuate, fanned, extensionof z-filter media. The media pack 600 can be formed from one or morestacks of media. The media pack 600, then, comprises multiple arcuatesections, each carved in the same general direction (i.e. convex sideout, concave side in).

A media pack in accord with media pack 600 can be incorporated into anair filter cartridge; for example by having end pieces in accord withthe arrangement of FIG. 30, although alternatives are possible.

In FIG. 47, an additional, alternate, media pack 650 is depicted,extending with a generally M- or W-shape. End pieces can be positionedover opposite sides 651, 652 with an appropriate housing sealarrangement, to allow for filtering flow in the general direction of (oropposite to) arrows 655, as an example. It is noted that the media pack650 can be formed from one or more stacks of media. Further, it is notedthat a characteristic of the media pack 650 is that it has multiplearcuate sections, at least which two (adjacent) of which are curved indirections oppositely to one another. By “oppositely” in this context,it is meant that when looking at one of the flow faces 650, 657, atleast one convex arcuate section and at least concave arcuate sectionare observed.

In FIG. 48 yet a further media pack 670 is depicted, here having ageneral arrow, arrowhead, or v-shape. Again, housing pieces could bepositioned over opposite sides 671, 672 to provide filtering flow in adirection corresponding to one of the directions indicated by doublehead arrow 675.

VII. Some General Comments and Observations

According to the present disclosure, filter assemblies and componentstherefor, as well as methods of assembly and use, are described. Thereis no specific requirement that an apparatus or method include all ofthe features, characteristics or steps described herein, to obtain somebenefit according to the present disclosure. There is also norequirement that an apparatus or method only include features,characterizations or steps described herein, to obtain some benefitaccording to the present disclosure.

According to an aspect of the present disclosure, a filter cartridge isprovided. The filter cartridge can be an air filter cartridge, forexample. The filter cartridge generally includes a media pack comprisingat least a first stack including a plurality of single facer stripsdefining opposite inlet and outlet flow faces. Each one of the pluralityof single facer strips comprises a sheet of fluted media secured to asheet of facing media. The stack (of single facer strips) includes astacking bead between adjacent single facer strips. The various stackingbeads are typically each positioned adjacent a selected one of the flowfaces of the media pack. By the term “adjacent” herein, it is meant thatthe stacking beads are either aligned with a selected flow face, or arespaced therefrom, but are relatively close thereto. Typically, then, thestacking bead is closer to one flow face than the other. Typically thestacking beads within the stack of (single facer strips) are positionedwithin 25 mm, typically within 12 mm and often within 5 mm of theselected flow face. In this context, the reference to the position ofthe stacking bead “within” a distance, means that at least an edgeportion of the stacking bead is within that distance, and reference isnot meant necessarily to the entire width of stacking bead.

Often, the stacking beads are positioned adjacent the outlet flow faceof the media pack. However alternatives are possible; for example,arrangements are described herein in which the stacking bead is adjacentthe inlet flow face of the media pack.

Herein, media packs are characterized in which the first stack (ofsingle facer strips), or at least a portion thereof, is configured in anarcuate configuration. By the term “arcuate” in this context, it ismeant that the stack (or portion of stack) is bent or curved over anarcuate shape; however no specific shape of arc is meant to bereferenced, and it is not meant to be referenced that a single,constant, curvature is necessarily provided, unless otherwise stated. Insome examples characterized, the arcuate curvature is typically eithercircular or elliptical; however alternatives are possible. The arcuateportion or configuration is in at least in a portion of at least one ofthe inlet and outlet flow faces; and, typically is in opposite portionsof each, one side being convex the other side being concave.

It is noted that within a given media pack, more than one arcuatesection or configuration can be provided, and in at least one exampledescribed, two oppositely curved arcuate sections are provided in thesame media pack.

Further, the media pack can be formed from more than one media stack,with one or more of the media stacks having curved or arcuate sectionsor configuration therein. It is noted that adjacent media stacks, in apack, need not necessarily all be positioned with the stacking beadadjacent the same flow face.

In some example configurations characterized herein, the arcuate sectionor configuration is formed by providing therein fanned strips. Herein,the term “fanned” is meant to indicate that adjacent strips of singlefacer, in an arcuate section, do not extend parallel to one another, butrather diverge outwardly from one another in extension from adjacent oneflow face toward the other flow face. Typically the outward divergence,is an extension from the outlet flow face toward the inlet flow face.When this is the case and the stacking bead is adjacent the outlet flowface, it may be said that the single facer strips are “fanned apart”adjacent the inlet face or inlet flow face, relative to the outlet flowface. This can be accomplished by spreading apart strips or layersadjacent the inlet flow face.

Alternately, in some configurations the stacking bead is adjacent theinlet face, and the arcuate shape results from compressing together endsof strips adjacent the outlet flow face. Alternately stated, the layerscan be spread apart adjacent an outside arc and be diverged; and, insome instances they can be compressed together adjacent an inside arc

In a typical arrangement characterized herein, a stack (or stackportion) of single facer strips is configured with an arcuateconfiguration (section) extending over an internal arc of at least 30°,although alternatives are possible. By the term “internal arc” in thiscontext, reference is meant to an angle between opposite end strips ofthe stack (of single facer strips) in the arcuate portion, which anglealso extends through the media pack.

It is noted that the arcuate configuration can extend over an internalarc of up to 360°. When the arc is 360°, the stack of single facerstrips is curved in a complete loop, around an open filter interior.Such a construction is sometimes referenced herein as “closed loop”construction. In a closed loop construction, the open filter interior istypically positioned adjacent the outlet flow face of the media pack,although alternatives are possible. It is noted that an example closedloop is provided herein, in which the media pack comprises a arcuatesection separated by straight side sections, and thus the arcuatesections do not extend over an internal arc of 360°.

It will typically be that the stack of single facer strips (or stackportion) is configured with one or more arcuate configurations, orsections extending over an internal arc within the range of 30°-360°,inclusive. However, smaller arcs, for example 10°-30°, inclusive, can beused with some media packs according to the present disclosure.

When the media pack is configured in a closed loop, the closed loop canbe provided with a variety of alternate cross-sectional configurations.An example is shown, in which the cross-sectional configuration isgenerally circular. An alternate configuration is shown, in which thecross-sectional configuration is oval, an example oval configurationcharacterized herein being elliptical. Herein the term “oval” in thiscontext, is generally meant to refer to a cross-sectional configurationwhich is not circular, but which does have two opposite curved (orrounded) ends; and, which generally has a longest cross-section and ashortest cross-section orthogonal to one another. A shape which has twoopposite curved ends, and two opposite sides extending between therounded ends, which sides have central straight sections extendinggenerally parallel to one another over an extended distance, would beincluded in the meaning of “oval”. Such a shape, in some instances, maybe characterized as “race track”. Another shape which is intended to bewithin the meaning of “oval” as used herein, is elliptical.

Another example shape characterized herein, is one in which, incross-section, the media pack can be characterized as configured withtwo sets of opposite parallel side sections, joined by four (4) curvedcorners.

Example cartridges are characterized herein, in which the media pack ispositioned in extension between first and second end pieces; at leastthe first end piece including an aperture therethrough in air flowcommunication with an open, central, volume. An example such filtercartridge includes a seal member positioned on a side of the first endpiece opposite the media pack. An example such seal member is depicted,which comprises an axial framework or housing seal, oriented for sealingengagement with a portion of a frame or housing during installation ofthe cartridge in an air cleaner assembly.

An example filter cartridge is characterized herein in which theaperture through the first end piece is a circular aperture. In analternate example also characterized herein, the aperture through thefirst end piece is an oval (for example elliptical) aperture. Typically,a circular aperture will be used with the media pack having a circularcross-sectional configuration; and, an oval (for example elliptical)aperture will be used with a media pack having an oval (for exampleelliptical) cross-sectional configuration, but alternatives arepossible.

In some example cartridges characterized herein, the second end piecealso includes an aperture therethrough, in air flow communication withthe open central volume. Further, the cartridge includes a second sealmember positioned on a side of the second end piece opposite the mediapack, the second seal member typically comprising an axial framework orhousing seal member. The aperture in the second end piece can have avariety of shapes, example shapes corresponding to a circular shape andan elliptical shape. While alternatives are possible, a typical shape ofthe aperture in the second end piece, as with first end piece, willgenerally correspond with the cross-sectional shape of the media pack.

Example elliptical (oval) cartridges are characterized herein, in whichthe aperture(s) through the end piece(s), when oval shaped, is (are)also elliptical, with a length ratio of longest axis-to-shortest axiswithin the range of 2.1 to 1.3, inclusive. It is noted that alternativesto this can be practiced with techniques characterized herein.

When a cartridge comprises a media pack extending between first andsecond end pieces, and the end pieces have an aperture therethrough, theend pieces can be molded-in-place, or they can comprise a preformedconstruction, for example, a metal or plastic construction, to which themedia pack is potted (i.e. secured). The housing seal member positionedon the various end pieces, can be preformed and be attached thereto withadhesive, or can be molded-in-place. For example, the end pieces cancomprise sheet metal cut and shaped into the appropriate shape; and, theseal member can comprise a polymeric gasket adhered to the metal endpiece with adhesive. In an alternative, the end pieces can comprise,molded-in-place, polyurethane; with the seal members comprising soft,compressible, molded-in-place foamed polyurethane.

Also characterized herein are filter cartridges in which the media packis positioned with the single facer strips extending between first andsecond molded-in-place end pieces. Example molded-in-place end pieceswill comprise polyurethane foam. A useable soft, molded-in-placepolyurethane foam for this purpose, would be a foam having an as moldeddensity no greater than 30 lbs/cu. ft. (0.46 g/cc) typically no greaterthan 15 lbs/cu. ft. (0.24 g/cc) and often no greater than 10 lbs/cu. ft.(0.16 g/cc); and, having a hardness, shore A, no greater than 30,typically no greater than 25 and often within the range of 12-20,inclusive, although alternatives are possible.

These constructions can be configured with a variety of types offramework or housing seal arrangements, and several examples aredescribed. In one example, the framework or housing seal arrangementcomprises a pinch seal molded-in-place in extension peripherallycompletely around a media pack and across the end pieces. A secondexample is provided in which the framework or housing seal arrangementcomprises a radially directed seal, projecting from a flow face(typically an outlet flow face) of the media pack. A third examplesystem is characterized in which the framework or housing sealarrangement comprises a seal member surrounding an outlet flow aperturein one of the end (side) pieces.

Example arrangements are described, in which the media pack has at leasttwo curved arcuate sections, spaced from one another. An example isprovided in which the at least two spaced curved arcuate sections areoppositely curved.

Another example arrangements are described herein in which the mediapack is formed from more than one stack of media. Also examples aredescribed in which the media pack is one or more blocked stacks, andother examples are described in which the media pack is made from one ormore slanted stacks.

An example filter cartridge is provide herein having an arrow shape witha vertex and two sides.

Also according to an aspect of the present disclosure, an air filterassembly is provided. The air filter assembly generally includes ahousing comprising housing body and an access cover, the housingincluding an air flow inlet and an air flow outlet. At least one (first)air filter cartridge in accord with selected ones of thecharacterization previously provided, is operably positioned within thehousing, and generally is removable therefrom when the access cover isopen. The (first) cartridge is typically sealed in the housing in such amanner such that air flow from the air flow inlet to the air flow outletmust pass through media of the media pack. A preferred configurationwould be with the (first) air filter cartridge oriented such that thefanned face of the media pack, toward which the single facer stripsdiverge away from one another, is positioned as an inlet flow face. Whenthe (first) cartridge is configured with the media pack as a closedloop, this would correspond to the outer periphery of the media pack.

The various features previously characterized for a filter cartridge canbe incorporated in the air filter cartridge. In addition, the housingcan be configured for positioning therein of more than one filtercartridge. An example housing is depicted that is configured forpositioning therein of at least two, and in the example two, filtercartridges during use; the two cartridges being positioned verticallydisposed with respect to one another, i.e. with one cartridge above theother. In the particular example depicted, each cartridge has anelliptical (oval) shape, and the cartridges are positioned with a longeraxis of the elliptical (oval) shape oriented generally vertically.

In some applications of the techniques described herein, a filtercartridge has a closed loop configuration, and the housing includes atleast one venturi member in air flow communication with an open,central, volume of the closed loop media pack.

In an aspect of the present disclosure, the air filter assembly includesa reverse pulse jet air cleaning system. In general, a pulse jetcleaning system is a system configured for selected direction of a pulsejet of gas (typically air) through the media pack of a filter cartridgein a direction opposite to a normal filtering flow, i.e., in a pulse jetdirection from the outlet flow face toward the inlet flow face. Such apulse of gas (air) will tend to blow dust off of the filter cartridge,for collection in a bottom of the air cleaner housing, and typically tobe ejected therefrom by a dust ejector arrangement.

A typical pulse jet cleaning assembly includes a pulse jet valve/pulsedirector configured to selectively direct a pulse jet of gas typically(air) into the media pack. Typically in examples characterized herein,this pulse jet is directed through a tube sheet or wall, into aninterior of the media pack. The assembly can include multiple pulse jetvalve/pulse directors. In general, the pulse jet valve comprises avalve, for example actuated with solenoid switch central arrangementthat opens to allow a pulse jet of gas from a compressed air tank topass therethrough, selectively. A pulse director, typically a tubeconnected to or associated with the valve, is configured to direct apulse from the valve in a selected direction. The term “pulse jetvalve/pulse director” and variants thereof is meant to refer to operablecombination of a pulse jet valve and pulse jet director.

A particular assembly is depicted, in which each media pack isassociated with a venturi assembly. The venturi assembly is configuredfor passage therethrough of filtered air coming from the filtercartridge, and, in an opposite direction, a pulse jet from the pulse jetvalve/distributor arrangement. The term “venturi” is generally meant torefer to a tube with has flared ends connected by a constricted middle,that provides for a venturi effect in flow or gas therethrough.

An example assembly is depicted, in which each air filter cartridge isassociated with at least two at least venturi members, each venturimember being aligned for gas flow communication with an interior thesame cartridge. The pulse arrangement includes a separate pulse jetvalve/distributor arrangement associated with each venturi member. (Insome alternate applications each air filter cartridge is associated withonly one venturi member).

An example depicted configuration is one in which the cartridge has agenerally oval (for example, elliptical) cross-sectional shape, with anoval (generally elliptically) shaped interior associated with twoventuri members, of a venturi arrangement. The venturi members wouldtypically be oriented vertically with respect to one another, and thecartridge would typically be oriented with a longer axis orientedvertically.

A yoke arrangement can be positioned within the housing, with an airfilter cartridge fit thereover. In an example described, the yokearrangement includes a first pair of vanes configured to form a barriervane arrangement extending across an interior of a cartridge fitthereover. Each vane of a “barrier” vane arrangement, is typicallyimpermeable gas to flow therethrough.

In an example characterized herein, the yoke arrangement includes asecond pair of vanes forming a second vane arrangement extendinggenerally orthogonal to the first (barrier) vane arrangement, with avane extending on opposite sides of the first (barrier) vanearrangement. In an example depicted, the second pair of vanes ispermeable, i.e., each one of the second pair has gas flow aperturestherethrough.

In general terms, the vane arrangement comprises multiple vanes forminga yoke over which the cartridge is mounted, during installation. Whenthe air cleaner assembly is configured for more than one cartridge, itcould include more than one yoke.

In the example arrangements described herein, vane arrangements arecharacterized which include two pair of vanes; a first pair forming thefirst (barrier) vane arrangement and a second pair forming the secondvane arrangement orthogonal to the barrier vane arrangement.

In an example arrangement depicted herein, a cartridge having an oval(for example elliptical) interior is fit over a yoke, with the barriervane arrangement extending across an interior of the cartridge. Thecartridge is aligned with two venturi members, each of which is orienteddirect air flow to an opposite side of the barrier vane arrangement,from the other.

The air filter assembly can include a charge tank for compressed gas(typically air) to be used for the pulse jet. The assembly can includean appropriate control arrangement, for selective actuation to directpulse jets as desired.

From the above general characterizations and descriptions, a variety ofapplications, techniques and features characterized herein can beunderstood. Again there is no specific requirement that an assembly orapplication include all of (or only) the features characterized herein,to obtain some benefit.

What is claimed:
 1. An air filter cartridge comprising: (a) a media packcomprising at least a first stack including a plurality of single facerstrips defining opposite inlet and outlet flow faces; (i) each one ofthe plurality of single facer strips in the first stack comprising asheet of fluted media secured to a sheet of facing media; (ii) the firststack including a stacking bead between adjacent single facer strips;(iii) the first stack including at least a first portion configured inan arcuate configuration of individual single facer strips oriented withrespect to one another to form the arcuate configuration having aninternal angle of at least 10° and less than 360°, in at least a portionof at least one of the inlet and outlet flow faces; (iv) the media packbeing closed to passage of unfiltered air completely therethrough; (v)the media pack being positioned in extension between first and second,opposite, end pieces; and, (b) a seal member positioned in extensionaround the media pack.
 2. An air filter cartridge according to claim 1wherein: (a) the first portion of the first stack, that is configured inthe arcuate configuration, defines an arcuate portion in the outlet flowface and an arcuate portion in the inlet flow face; (i) the single facerstrips within the arcuate configuration being fanned apart adjacent aflow face.
 3. An air filter cartridge according to claim 1 wherein: (a)the media pack is positioned with the single facer strips extendingbetween first and second, opposite, molded-in-place, end pieces.
 4. Anair filter cartridge according to claim 1 wherein: (a) the media packcomprises a plurality of stacks each of which includes a plurality ofsingle facer strips.
 5. An air filter cartridge according to claim 4wherein: (a) each one of plurality of stacks includes at least oneportion configured in an arcuate configuration.
 6. An air filtercartridge according to claim 5 wherein: (a) the filter cartridgecomprises two stacks each of which comprise a slanted stack.
 7. An airfilter cartridge according to claim 1 wherein: (a) the media packincludes a plurality of arcuate sections.
 8. An air filter cartridgeaccording to claim 7 wherein: (a) the media pack includes at least two,spaced, oppositely curved arcuate sections.
 9. An air filter cartridgeaccording to claim 1 wherein: (a) the media pack is formed from at leastone blocked stack.
 10. An air filter cartridge according to claim 1wherein: (a) the media pack is formed from at least one slanted stack.11. An air filter cartridge according to claim 1 wherein: (a) a stackingbead in the first portion of the first stack is positioned adjacent aninside arc of the arcuate configuration.
 12. An air filter cartridgeaccording to claim 1 wherein: (a) a stacking bead in the first portionof the first stack is positioned adjacent an outside arc of the arcuateconfiguration.
 13. An air filter cartridge according to claim 1 wherein:(a) the media pack has opposite end strips and is arcuate in completeextension therebetween.
 14. An air filter cartridge according to claim13 wherein: (a) the internal angle is less than 180°.
 15. An air filtercartridge according to claim 14 wherein: (a) the internal angle issmaller than a right angle.
 16. An air filter cartridge according toclaim 14 wherein: (a) the internal angle is within the range of 10°-30°,inclusive.
 17. An air filter cartridge according to claim 14 wherein:(a) the internal angle is at least 30°.
 18. An air filter cartridgeaccording to claim 1 wherein: (a) the internal angle is less than 180°.19. An air filter cartridge according to claim 1 wherein: (a) theinternal angle is smaller than a right angle.
 20. An air filtercartridge according to claim 1 wherein: (a) the internal angle is atleast 30°.